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Essentials of Material Logic Page 2

UNIVERSITY OF CALICUT

SCHOOL OF DISTANCE EDUCATION

STUDY MATERIAL

Core Course

B A Philosophy

IV Semester

ESSSENTIALS OF MATERIAL LOGIC

Prepared by

Module I & II

Dr. V. Prabhakaran, Principal, EKNM Govt. College, Elerithattu, Kasargod.

Module III , IV & V Dr. Babu M.N, Assistant Professor, Department of Philosophy, SSUS, Kalady.

Scrutinised by: Dr. V. Prabhakaran, (Co-ordinator), Principal, EKNM Govt. College, Elerithattu, Kasargod.

Layout: Computer Section, SDE

© Reserved



CONTENTS PAGES

UNIT I - INTRODUCTION 5

UNIT II - KINDS OF INDUCTION 9

UNIT III - OBSERVATION AND EXPERIMENT 15

UNIT IV - CAUSAL CONNECTION 24

UNIT V - HYPOTHESIS 36





UNIT I

INTRODUCTION

What is Induction?

The systematic nature of reality is the basis of all inference. It is by virtue of the interconnectedness of things that we pass in knowledge from one element to another. It is the whole system of reality that is the ground of inference. The principle of deductive inference is the application of a universal or or system to any member thereof. This presupposes a process by which the universal or system is established. The process by which universal is arrived at is called induction.

The main business of any science is to establish general principles or law –like statements . The general principles of science are arrived at on the basis of particular facts. The process of arriving at general principles is called generalization or induction. Induction is the method by which universals are discovered. Universal or general statements are derived from particular facts. Induction is the process of discovering and proving general propositions. Induction is the process of inferring a universal proposition from particular facts. Induction is a mental process of reasoning by which a universal law is discovered and proved from the study of particular facts observed around us. Inductive logic is the logic of scientific discovery.

The universal is the soul of deductive reasoning. Deduction cannot guarantee the material truth , the only aim of deduction is formal truth. Deduction leave us with universal propositions which it cannot prove. To arrive at universals is induction. Induction examines only a few observed particular facts and arrives at a universal proposition out of the particular facts. For example, from the particular facts of heating metals like iron, silver, gold etc and observing expansion of metals upon heating, the universal proposition that‘ all metals expands when heated ‘ is derived.

The problem of Induction

The problem of induction is: ‘How are the premises of deductive reasoning established? ‘Since induction provides the material truth of inference, it has been called material logic. The aim of science is to explain individual facts that are experienced. To explain a fact is to relate it to the law by which it is governed. It is the laws or systems that make the individual facts intelligible. The purpose of science is to discover these laws. This is done by discovering the wider law of which it is an aspect. Science generalizes from particular facts which are experienced. The process of generalization is called induction. Thus inductive logic may be described as the logic of the scientific method. Whatever be the science, there is a common method of generalization. It is this method that is the



subject of study in inductive logic. Induction is the process by which facts are induced to disclose the universal that connects them while deduction is the process of reasoning which deduces from the system or universal the character of a member of the system or a fact coming under the universal.

Induction jumps from a few known instances to all instances. This jump from some observed cases to all cases is known as inductive leap or hazard. What is the justification for a jump from a few known instances to all instances ? This is the problem of Induction. The task of Induction is to justify the jump from ‘some’ to ‘all’ and to show how we can infer a universal proposition from a few particulars observed by us. The problem of Induction is how a general proposition can be arrived at from a few particular facts. The function of Induction is to discover universal propositions and to verify and prove the material truth of universal propositions. The material truth of universal propositions as premises of deductive arguments is provided by Induction. Deduction assumes the material truth of universal propositions. Induction prove and guarantee the material truth of universal propositions.

Induction and Deduction

In deduction we draw a conclusion consistent with the given premises. The aim of deduction is the formal validity, while Induction aims at the material truth .Since Deduction guarentees only the consistency of the conclusion with the given premises(formal validity), Deductive logic has been called the logic of consistency. The form or structure of inference is the sole concern of Deduction, hence called Formal Logic. Induction aims at the material truth of the arguments. It enquires whether the universal agrees with the actual facts or not. In Induction we are concerned with the matter expressed in the arguments, whether the matter agrees with the actual facts of the universe or not. Induction is therefore called Material Logic.

Induction is the process by which facts are induced to disclose the universal that connects them, deduction is the logical process of deducing from the universal the character of a member of the universal. Bacon describes induction as an ascending process and deduction as a descending process. In induction we mount up from the particulars to the universal whereas in deduction we get down from the universal to the particulars.

In Deduction the conclusion is either particular or less general than the premises out of which it is derived. In Induction, the conclusion is is always greater than the premises.

In spite of the differences between Induction and Deduction, they are not two kinds of reasoning which are quite distinct, independent and even opposed to each other. They are two aspects of one and the same process of reasoning. The relation between Induction and Deduction consists in showing the way in which a system or whole is constituted. Both show how facts are necessarily connected together by a universal law. Without deduction, the conclusion of an inductive reasoning will not be universal and necessary; without induction , deductive reasoning will not have content wherewith to proceed. Deduction



without induction is empty; induction without deduction is blind. The only distinction between the two is as regards the starting point and mode of procedure. Deduction starts with a universal and proceeds to see if it is realized in a particular case. Induction starts with the particular cases and constructs the system of which they are members. Deduction and Induction are interdependent on each other. Deduction provides the formal validity or formal truth, while Induction provides the material truth. Induction and Deduction are necessary for scientific enquiry.Both are complementary.

Postulates of Induction

The problem of induction is to arrive at universal propositions on the basis of our experience of particular facts. We need a method by which universal propositions can be established. The method by which universal propositions are discovered is induction. The question arises: by what right do we generalize? If there were no universals , if facts were not bound to one another by principles of connection, no amount of rearch for universals would be of no use. Hence induction has to assume that there are universals. To understand a thing is to apprehend it in its place tin a system. It is the system that makes the thing intelligible. Induction postulates that the world is an organic unity. That it is a cosmos and not a chaos , a universe and not a multiverse. This principle or postulate of the systematic nature of the universe has been expressed in several ways, of which two are important. They are, (1) the law of Universal Causation (2) the principle of the Uniformity of Nature.

Induction is based on two fundamental principles, the law of causation and the law of uniformity of nature which are called the postulates of Inductioin. The answer to the problem of Induction lies in the two fundamental principles, the Law of Causation and the Law of Uniformity of Nature. The law of causation states that every event has a cause. Whatever exists has a cause. There is no causeless event. The law of Uniformity of Nature states that the same cause produces the same effect under the same conditions. Nature behaves in the same way under similar conditions. By Uniformity of Nature we mean that nature is orderly and systematic. Everything that happens in the world happens according to law and the nature is a system of laws.

The law of universal causation:

One way of expressing that the universe is systematic is to say that everything which has a beginning must have a cause. Out of nothing, nothing comes. Ex nihilo nihil fit. There can be no uncaused event. Whatever be the event, it must have a set of conditions without which it cannot occur, and given which it must occur. This is known as the law of universal causation.

The law of uniformity of nature:

Another way of giving expression to the systematic character of the universe is to say that nature is uniform , that what is once true is always true. The principle of uniformity adds, the same event must have the same cause. This principle means that



nature is consistent and not chaotic. The principle of uniformity of nature is wider than the law of universal causation. All things in the universe are not related as causes and effects. There are other relations like co‐existence, whole and part etc. All these also come under the principle of uniformity.

The postulates of induction cannot be proved. The principle of uniformity is a postulate and cannot be proved because like the laws of thought it is the basis of all proof. If there is to be the possibility of knowledge, one must accept the principle of uniformity as a fundamental postulate of thought. It is not the task of induction to prove uniformity. Assuming general uniformity in nature, induction proceeds to discover particular uniformities. Hence the principle of uniformity has been called the ultimate major premise of all induction.

Can the postulates be proved?

It has been held by empiricists like Mill that the postulates of induction are the result of induction from experience. But the empiricist view will not stand examination. First, it involves the fallacy petition principia. In order to prove the principle of uniformity the empiricist has to assume the principle. Having observed particulars, limited uniformities, the empiricist uses them as a guide to general uniformity.

Further, we in our limited experience meet with uniformities and infer there from the uniformity of Nature in general. We experience irregularities also. If we look for uniformities behind irregularities , it is because of a faith in the systematic character of Nature. But faith itself cannot be the result of experience.

The principle of uniformity is a postulate and cannot be proved, because like the laws of thought, it is the basis of all proof. It is not the task of induction to prove uniformity. It cannot do it. Assuming general uniformity in nature, induction proceeds to discover particular uniformities. Hence the principle of Uniformity has been called the ultimate major premises of all induction.



UNIT II

KINDS OF INDUCTION

Induction by enumeration (Enumerative induction)

Enumerative Induction is a method of making a universal proposition on the basis of a mere number of observed instances. It is a process of simple counting the instances of the phenomenon under investigation. . It is a mere counting of instances. The schoolmen of the Middle Ages divided induction into two kinds: (1) Perfect induction (2)Imperfect induction Enumerative Induction is of two kinds. (1) Perfect Induction or Induction by complete counting.

(2)Imperfect Induction or Induction by simple enumeration.

(1) Perfect Induction or Induction by complete counting.

Perfect Induction is arriving at a universal proposition after counting all the individual instances .It is a generalization based on complete counting of all the instances. In perfect induction we observe each and every instance and express the result in the form of a universal proposition.For example, after observing each and every fruit in a basket make the proposition that all the fruits in the basket are apples. We count the number of days in each month of the year and make the general statement that all months of the year contain less than thirty‐two days each. Perfect Induction is exhaustive and complete enumeration of all the instances and the universal proposition arrived at by this method is absolutely certain. Perfect refers to the completeness of counting.

Limits of perfect induction: It is only a summation of several observed instances. The view has been criticized by most of the writers on scientific induction. The business of induction is not to count instances. Counting cannot give an explanation of facts. Perfect induction is not at all genuine induction.The proposition arrived at by perfect induction is not a genuine universal proposition, but a universal proposition in appearance. It is only a collective universal. It is only a shorthand registration of known facts. There is no new knowledge.

Further, there is no inductive leap. Inductive leap is an important characteristic of genuine induction. Perfect induction refers primarily to the number of instances and not their nature or qualities.

Merits of perfect induction:

The proposition arrived at by the method of induction is certain. Further, expressing a great number of particular facts in a very brief form is very essential to the progress of science.



(2) Imperfect Induction or Induction by simple enumeration.

The method of incomplete counting is called imperfect induction. It is also called induction by simple enumeration. Imperfect Induction is a method of arriving at a universal proposition after counting only a few instances of the phenomenon under investigation. In this method we observe only some instances and then make a universal proposition which applies to all the instances of the phenomenon. For example, after observing a few short men who are unreliable, we make a general statement that all short men are unreliable. In imperfect induction we count some instances only and make a general statement covering not only the observed instances but also the unknown instances. We count several crows, notice their black colour and make the general statement ‘All crows are black’.

Merits of Imperfect Inductiion: The characteristic of induction is inductive leap. The method of imperfect induction has inductive leap. In imperfect induction there is a jump from some to all. After observing a few instances, it generalizes about all. There is a march of information, new knowledge.

Further, it is based on the postulate of Uniformity of Nature because generalization is made on the belief that the unobserved instances would also behave in the same way as the observed instances. Again, it is very useful in cases where the number of instances is unlimited and counting all instances is impossible. Imperfect induction suggests good hypothesis. The value of imperfect induction lies in it’s power to suggest causal relation. In fact, imperfect induction prepares the ground for inductive enquiry.

Defects of Improper Induction: Simple enumeration is not the method of induction that is employed by science. Imperfect induction is unscientific since it counts only a few instances and it is simply a descriptive and not an explanatory method. Sufficient to make the universal statement false. There is always the possibility of a contradictory instance.

This method commits the fallacy of Hasty Generalisation. The fallacy of hasty generalization consists in generalizing from a few favourable instances ignoring or not considering unfavourable instances. The conclusion obtained through simple enumeration is only probable and never certain.

Parity of Reasoning

Under the heading ‘Inductions improperly so‐called’, Mill includes, besides perfect induction, two other processes called ‘Parity of reasoning’ and ‘colligation of facts’. Induction by parity of reasoning is the process of establishing the truth of a general proposition on the ground that the same reasoning which proves a particular case will also prove every other similar case covered by the general proposition. On the basis of this knowledge we say that all triangles have their three angles equal to two right angles. The principle of inference here is that the method of proof in the case of one triangle is the same as that in any other. This is called induction by parity of reasoning. Mill characterizes



this method as ‘induction improperly so‐called’ because the essential of induction , observation of facts is not present here. Geometrical reasoning does not depend on observation or sense‐experience.

Colligation of Facts.

Colligation of facts is making a mental union of facts observed by means of a general conception. Kepler observed planet Mars in different positions in it’s orbit and brought those positions together under the general conception of an ellipse. Mill defines colligation as that mental operation which enables us to bring a number of actually observed phenomena under a description.

According to Mill, colligation of facts is not induction proper. It gives us merely a summary of the various observations, like the so‐called perfect induction. Colligation is descriptive of facts, it does not explain them.

Induction by Analogy

Analogy is a method of Induction in which a more complete resemblance between things is inferred from their partial resemblances in certain points. Analogy is a form of reasoning in which from the resemblances of two or more things in certain respects their likeness in other respects is inferred. For example, the planets Earth and Mars resemble each other in certain respects: both have day and night, both have land sea and atmosphere, both rotate round the sun and borrow light from the sun, both revolve on their own axis . The Earth is inhabited by men. So Mars also is inhabited by men. In Analogy, the principle of inference is similarity.

Conditions(Rules) of a good or sound analogy.

1. The points of resemblance must be essential and relevant to the conclusion drawn The qualities of resemblance must be really connected with the inference drawn. For example, from the similarity between two students in certain respects such as colour, hair style, mode of walking, way of speaking, age, diet, weight height etc , to infer that one being intelligent the other is also intelligent. In this inference, the similarities are irrelevant to the point of inference. The points of resemblances have no necessary connection to the point of intelligence. Hence, the analogy is bad or unsound. Mere number of similarities is not of much use. The value or strength of analogical inference depends not on the number of similarities but similarities on essential and relevant qualities to the inferred quality.Quality and not quantity of similarity be the criterion of perfect analogy. If the points of similarity are both essential and numerous, then the greater the value of analogy.

2. There should not be essential or fundamental differences between the things compared with respect to the inferred quality. Not only the resemblances must be essential , the differences must be superficial. The less the number and importance of the points of difference, the greater is the value of the analogy. For example, whales and sharks resemble each other in their shape, in their food, in living under water, in having back



bones etc. Therefore, whales like the sharks breath the oxygen from water. This is an unsound analogy because while sharks have a special organ ‘gills’ necessary for breathing the oxygen from water, whales do not possess ‘gills’.

3. Analogy must be based on fairly extensive knowledge of the things compared. If our knowledge of the things is not exhaustive, we cannot know all the essential points of resemblance and the important differences between them. For example, Democracy cannot succeed in India, because it failed in China. This is false analogy because it is based on limited and imperfect knowledge of the conditions existing in India and China. A sound analogy is one in which the conclusion is based on the presence of essential resemblances, the absence of essential differences and an extensive knowledge of the things compared. An unsound analogy is one in which the resemblances are superficial, the differences are essential and our knowledge of things is very little.

The value (use) of Analogy

Analogy helps in suggesting hypothesis. By suggesting hypothesis, analogy has led to scientific discoveries. Analogy as a method of discovery has played an important role in the progress of science. On the analogy of sound, it was discovered that light too travels in waves. The analogy which Newton perceived between an apple falling to the ground and the heavenly bodies falling in space led to the discovery of the of gravitation. Analogy is superior to enumerative induction. While enumerative induction merely counts instsances, analogy analyses the similarities between phenomena. Analogy stands midway between enumerative induction and scientific induction.

Defects of analogy

Analogy gives only probable conclusion. Analogy is an incomplete process of induction. It is a mere guide post pointing to the direction in which more investigations are to be held.

Scientific Induction

Scientific induction is a process of establishing a universal proposition from an observation and analysis of a few particulars of our experience. It is a process of generalization from the study and examination of a few particular facts. For example, Heat expands metals.

Characteristics of scientific induction:

The establishment of real general propositions is the main characteristic of scientific induction. A real proposition is one whose predicate states a quality added to the subject. Scientific induction aims at real propositions. In scientific induction, the nature of instances is more important than the number of instances. It is a general truth applicable to all the instances of the phenomenon under study, true for all time and space.



Another characteristic of scientific induction is that it is based on facts. It is the result of observing concrete facts occuring aroud us. Observation of facts is the material ground of induction. Scientific induction is based on analysis of particular facts. Scientific induction is based more on the analysis than on simple counting of instances. Inductive leap is another characteristic of scientific induction. Inductive leap means the passage From some observed particulars to the universal.

Stages of scientific induction.

1. Observation and analysis of facts.

Observation and analysis of facts is the first stage of scientific induction. Observation and analysis of facts supplies the materials of induction.

2. Formulation of hypothesis.

Framing a hypothesis is the second stage of scientific induction. It is an attempt to explain the observed fact, a guess , a provisional explanation of the observed fact . When Newton observed a fruit falling to the ground, he guessed that it may be due to the attraction of earth.

3. Verification of hypothesis

Verification means testing a hypothesis whether a hypothesis is true or false. Verification may be direct or indirect. In direct verification, the hypothesis is compared with actual facts by observation or experiment . For example, seeing a crowd at a distance guess that an accident has occurred. This hypothesis can be verified directly by going to the spot and see whether an accident has occurred or not.

In indirect verification, assuming the hypothesis to be true certain consequences are deduced and if the deduced consequences agree with the observed facts the hypothesis is verified ,if not it is given up or modified. For example, Galileo noticed water rising in a pump up to 33 feet. Torricelli, his pupil suggested a hypothesis that air must have weight and it is the pressure of this weight of air on the surface of water which forces it up the pump. The hypothesis was assumed to be true and the following consequences were drawn from it.

a) The weight of the air ought to lift mercury, which is 14 times heavier than water, only to 1/14 of the water height of the water height of 33 feet.

b)At the top of a high mountain where there is less air pressing downwards, the hight of mercury should fall considerably.

These two consequences were compared with actual events and they agreed with them. Thus the hypothesis was verified. To verify a hypothesis is not to prove it. Verification only shows that the hypothesis explain the given fact , but it does not establish it to be the only explanation. A verified hypothesis is called a theory.



4. Proof

The proof of a hypothesis consists in showing that the verified hypothesis is the only adequate explanation of the given phenomenon, and that there is no other hypothesis to explain it satisfactorily. When several theories seem to be acceptable for one and the same phenomenon, only one of them must be correct. To decide between the rival theories, the crucial instance is used. A crucial instance is an event which can be explained only by one of the several rival hypotheses. The word ‘crucial’ means a cross put up at road junctions to point out the proper to a particular place and to show that the other roads will not lead to the same place. A crucial instance enables us to find out the correct hypothesis and at the same time to reject the other hypotheses as false. For example, Queen Sheba wanted to test the wisdom of king Solomon, placed at a distance two rose flowers, 09one natural and the other artificial. King Solomon asked all the windows and doors of the hall to be left open. After some time bees came on and settled on one rose only to enjoy the honey from it. From this the king pointed out the real rose. In this example, the settling of the bees is a crucial instance which helped the king find out the real rose and reject the other as artificial. The theory which is proved is called a law.

Scientific induction is the process of establishing a universal proposition on the basis of the analysis of a few observed facts. It depends on analysis and not on mere counting. There is inductive leap. The provisional suggestion or unverified guess that is made for explaining facts is a hypothesis. When the hypothesis is verified it is called a theory. When the theory has been well established, it is called a law. Thus the three terms, hypothesis, theory and law indicate different stages in the process of explanation from the unverified tentative supposition to the well‐established law of Nature.



UNIT III

OBSERVATION AND EXPERIMENT

Introduction

It has been said that induction requires both formal and material grounds of generalization. The law of uniformity of nature and the law of causation are regarded as the formal grounds of induction. Some regard observation and experiment as material grounds of induction. So these two processes are called material grounds and supply material for inductive generalization. We start with collection facts, which are facilitated by observation. Further we try to analyze the facts and find out the causal connection between them. This is better facilitated by experiment. An experiment is regarded as an observation made under artificial conditions. Experiment becomes possible only when some knowledge has already been gained by the first material ground of induction and, in sciences, it remains the chief ground

The urge for knowledge is universal. Man by nature is so constituted that he can not but be inquisitive about himself and his surroundings. This urge for knowledge leads him to supplying materials to induction. We must distinguish between observation and mere perception and many of us look at nature but only a few observe nature. This means we should know what we have to observe to our purpose.

If our observation and experiment should be sound and accurate, it is necessary physically that the observer should possess sound sense organs. In observation and experiment a defective sense organs will lead to defective results. Francis Bacon pointed out that the mind must be free from all prejudices and preconceptions. Morally observation should be carried out impartially and without prejudice. In order to get correct observation, the observer requires patience . Observation also requires concentration, abstraction and well regulated imagination. Nature is a cosmos and not a chaos. There are lots of conditions necessary both for observation and experiment.

Most regarded observation as the first ground for induction .So observation is the only ultimate way of getting facts. Observation is not as simple and easy as it seems. Observation literally means keeping something before the mind. Scientific observers have to be trained to be accurate in distinguishing, in noticing and quick in selecting what is new and instructive. This clearly brings out the real nature of observation. Observation may be defined as a regulative perception which requires careful selection and concentration, and is conditioned by interest and purpose.



Observation of facts then is a cardinal part of the method of science. The facts on which our inferences are based, by which our conclusions are tested, must be accurate. But in thus laying emphasis on the necessity of accurate observation, we must beware of rushing to the opposite extreme, and supposing that observation alone is enough. Observation, the accurate use of the senses is not the whole work of science. We may stare at facts every minute of our waking day without being a whit the wiser unless we exert our intellects to build upon them or under them. To make our examination fruitful, we must have conceptions, theories, and speculations, to bring to the test. The comparison of these with the facts is the inductive verification of them. Science has to exercise its ingenuity both in making hypotheses and in contriving occasions for testing them by observation. These contrived occasions are its artificial experiments, which have come to be called experiments simply by contrast with conclusive observations for which nature herself furnishes the occasion. The observations of science are not passive observations. The word experiment simply means trial, and every experiment, natural or artificial, is the trial of a hypothesis. In the language of Leonardo da Vinci, “Theory is the general, Experiments are the soldiers”.

Observation and inference go hand in hand in the work of science, but with a view to a methodical exposition of its methods, we may divide them broadly into methods of observation and methods of inference.

There are errors especially incident to observation and errors especially incident to inference. How to observe correctly and how to make correct inferences from our observations are the two objects of our study in inductive logic. We study the examples of science because they have been successful in accomplishing those objects. That all inference to the unobserved is founded on facts, on the data of experience, need not be postulated it is enough to say that inductive logic is concerned with inference in so far as it is founded on the data of experience. But all the data of experience are not of equal value as bases of inference; it is well to begin with an analysis of them, if we wish to take a comprehensive survey of the various modes of inference and the conditions of their validity.

Observation with instrument

It is well that our sense have certain limitations. Man’s urge for knowledge makes him overcome the limitations and thus we find man has invented instruments that help him in this direction. We see distant things with the help of telescopes and with the help of microscopes A faint sound can be heard with the help of a microphone. The use of such instruments increases our field of observation .Instruments make our observation better, precise and accurate. Observation made with the help of instruments is possible without interfering observed objects. Instrumental observation holds an intermediary position between pure observation and experiment. In biology and astronomy this method is very useful.



Ordinary observation analyses the concrete given whole and selects certain parts of it for consideration before scientific observation begins. Scientific observation goes a stage further and performs more accurately and deliberately the processes than in ordinary perception. Scientific observation is to discover deeper uniformities, more exact classification, more comprehensive laws. This involves correcting the analysis, classifications, and interpretations, of ordinary thought. The scientist manipulates a fact in certain ways, introduces or removes conditions to see what will happen. Experiment may said to be observation under condition which we have prearranged.

Nature of observation Etymologically, the term observation means, “Keeping an object before mind”. However, in science observation means the selective perception of facts with a definite purpose. So observation differs from perception. Observation is an active process whereas ordinary perception is a passive process. Observation is a process of looking at thing with the purpose of determining their nature as accurately as possible. Observation is regulated perception of facts presented by nature. For instance, we observe eclipses, comets and so on. Observation can be defined as the objective, selective, systematic and concentrated activity of mind performed through the senses.

Characteristics of Observation

Observation is not merely looking at external objects that are mere perception. But observation is described as regulative perception. Regulative perception requires careful selection and concentration on the facts we observe. In observation we are selective because there is some purpose and we observe only those objects in which we are interested and ignore all other things. We must avoid observing wrongly or overlooking certain things. Our aim in observation is to secure correct information of the events that take place in nature and we should observe without prejudice or bias. In observation we only interpret what is given to us but we arrange the individuals observed and classify them into kinds according to various resemblances or identities.

Observation may be defined as a regulative perception which requires careful selection and concentration, and is conditioned by interest and purpose. It is well known that our senses have certain limitations. To overcome these limitations we use observation with instruments. The use of instruments increases our field of observation Instruments make our observation better, precise and accurate. E.g.,the case of a doctor using a stethoscope. In biology and astronomy this method is every useful.

Characteristics of Scientific Observation

a) Observation is selective

In observation we must select only those facts which are connected with the purpose. For instance, an artist and a botanist see a flower differently. The artists see mainly its beauty while the botanist sees mainly its structural arrangement.



b) Observation is teleological

Observation involves a definite goad or purpose. In observation we perceive things with a) Definite purpose.

c) Observation is unbiased.

Since our aim in observation is to secure correct information of facts we should observe things without any bias or prejudice.

Experiment

Experiment is preferable to observation It enables us to multiply instances. We can produce an effect under known conditions and so we can isolate antecedents. In experiment we can vary the conditions. And can observe with great care and precision. So results of experiment are more certain than those of observation. These features bring out clearly the advantages of experiment over observation. There are certain limitations to experiment. The heavenly bodies the winds and the movements of history are beyond our power to experiment with. The effect of poison on human body can not be studied by experiment. Similarly, if we want to study the effects of war or earthquake, we can not resort to experiment.

We find that Observation is passive experience and experiment is active experience. Observation and experiment differ not in kind but in degree as both are regulated perceptions. It can be said that experiment is more careful and accurate form of perception than observation. In experiment we can vary the conditions at our will because they are under our control.

It is difficult to differentiate observation and experiment. But it is drawn differently by different writers. Experiment has certain advantages over observation. In experiment, we can multiply the instances as often as we like. That is we can reap the phenomenon, as often as we like. But in observation we are at the mercy of the nature. We can observe only when the phenomenon re‐appears. In experiment, we can isolate a phenomenon and observe it under favorable and suitable conditions. In observation, which is dependent on nature, we can not isolate the phenomenon. In experiment we can study a phenomenon under varied circumstances. We can vary the conditions as we like. But in observation we have to depend upon nature for the presentation of the phenomenon.

In experiment we can observe and examine a phenomenon with greater care, precision, accuracy, and coolness of mind, because the phenomenon is under control. But in observation we have no opportunity to observe with the same degree of caution and precision.



Characteristics of experiment a) Experiment is preferable to observation

b) Experiment helps us to multiply instances

c) It is possible to produce an effect under known conditions and so we can isolate antecedents.

d) Vary the conditions in experiment.

e) In experiment we can give more care and precision

f) In experiment the results are more certain than that of observation.

g) There are certain limitations to experiment .E.g., the heavenly bodies, the earth movements of history, are beyond our power to experiment with.

h) We can’t study the effect of poison on the human body, the effects of war or earthquake.

I) Physical, chemical inquires and investigation in physiology and of plants the experiment is constantly practiced.

Similarities between observation and Experiment

Experiment is deliberate observation. In experiment we examine phenomena according to the terms we prescribe. It is deliberately designed to find out the answers to definite questions. Experiment involves variation of conditions.

Events and phenomena presented to us by nature are very complex. They are accompanied by many conditions. In experiment, the scientist can vary the conditions at will and determine which of them are relevant and which are irrelevant.

Experiment involves repetition; the conditions required for the experiment are under full control of the experimenter. Hence he can repeat the different stages of experiment as required. Moreover, others can also repeat the experiment in similar conditions.

Points to remember

Experiment is the process of collecting facts under artificially set conditions.

Experiment is controlled and deliberate observation.

Experiment involves variations of conditions and also repetition.

Observation depends on natural conditions whereas in experiment we make use of artificial equipments and conditions.



Observation is at the mercy of nature while experiment can be repeated at will.

Both observation and experiment are methods of collecting facts and hence the materials grounds of inductive inference. Hence, there is no essential difference between the two.

The difference between observation and experiment In observation it is the deliberate perception of an event that occurs in the course of nature and Phenomenon can be found .Humans have no control over the conditions .Observation is conducting at the mercy of nature. No variation of circumstances is possible in observation. The Progress in getting knowledge is slow and information is vague and uncertain. The scope of observation is unlimited and it proceeds from cause to effect and also from effect to cause.

On the other hand experiment is conducted in artificial conditions and by using artificial equipments and the phenomenon is made. In experiments conditions are under control and can be repeated at will for any number of times In experiment variation or alteration of circumstances is possible. So rapid advance in scientific knowledge is possible. More precision and accuracy leading to trustworthy results. The range of experiment is limited. In experiment we start from cause to effect only.

Experiment establishes causal connections with greater certainty. Observation is finding a fact .But experiment is making one. Experiment is observation under standard conditions that can be varied, repeated and isolated by the observer Experiment is more subtle and precise than observation.

Relative merits of observation and experiment

Advantages of Experiment

Control over phenomenon: In experiment the experimenter has full control over the phenomenon. Hence, he can repeat the different stages of experiment until he gets satisfactory results. A scientist who desires to understand the properties of a chemical compound can produce the compound as often as he likes.

Separation of various factors: Nature represents the phenomenon in complex surroundings. The experimenter can isolate the necessary factors for observation. Hence experiment helps one to concentrate on the relevant and necessary factors of the phenomenon. By means of experiment we can ascertain that it is the presence of oxygen in the atmospheric air that makes the burning of a substance like the candle possible. By an experimental analysis of air we can separate it’s constituents , fill different jars with the different gases, and by inserting a burning candle into each of the jars we can know that it is the oxygen content of air that makes the burning possible.

Variations of conditions: In experiment, one can alter the condition at will and observe the changes that are taking place in the phenomenon. Quantitative changes can be



brought about in experiment. But it is not possible in observation. Suppose we desire to know the condition which makes the audition of sound possible. We may increase or decrease the amount of air in a bell‐jar , and by striking the bell each time show that for the audition of sound the presence of medium like the air is necessary.

Accuracy of knowledge: Experiment can provide more accurate knowledge.

Cool and calm : In experiment we can be cool and calm ,and at perfect ease.

Advantages of observation

Observation is wider in scope: There are realms of reality which are beyond the scope of experiment. In such circumstances, one has to depend completely on observation. One cannot produce an eclipse or an earthquake. One has to wait for their occurrence and then observe.Thus observation is wider in scope.

Observation is prior to experiment. The scientist can conduct an experiment only after collecting sufficient data through observation. Observation prepares the way for experiment. Experiment is observation under control.

Reason From cause to effect and from effect to cause In observation one can proceed from cause to effect and also from effect to cause. But in experiment one can proceed from cause to effect only.

The phenomenon under observation has originality: The phenomenon artificially produced in experiment is not always the same as the phenomenon that we get in observation. In experiment, the scientist artificially sets up the necessary conditions. But in observation the scientist is dealing with original natural phenomenon.

Fallacies of observation

In the process of observation, there are many difficulties that may lead to certain errors or fallacies. The possible errors are non ‐ observation and mal ‐observation.

The fallacy of non – observation

Non‐observation means the failure to observe some conditions or factors which are actually necessary for the analysis. So non observation is a negative fallacy or it is a fallacy of omission. This fallacy arises either due to the complexity of the observed phenomenon or due to prejudices on the part of observer– non observation of instances and non observation of essential circumstances‐. The former consists of overlooking or omitting relevant instances or facts of the phenomena under observation. This can be due to neglecting the unfavorable physical conditions. The latter consists of focusing on unnecessary circumstances by neglecting the relevant circumstances.



Example, the popular belief like “the dreams of early morning will become true” and “the number 13 will always bring misfortune” are cases of generalization based on non observation. Similarly, the conclusions like “the good are inevitably happy and the wicked are unhappy” and “fortune favors fools” etc are also based on insufficient observation of instances.

The fallacy of mal – observation

Mal – observation occurs due to wrong interpretation of the observed facts. Hence what is perceived is misunderstood it involves wrong or mistaken observation and sometimes wrong explanation also. So it is a positive fallacy or a fallacy of commission. It consists of mistaking one thing for another. All kinds of illusions and hallucinations are examples of mal‐observation. E.g., the rope – snake illusion in dim light is a common instance of mal‐observation .

Quest: Explain the principles of observation and experiment in scientific inquiry

Ans:

The observational method is most common in the natural sciences, especially in fields such as biology, geology and environmental science. It involves recording observations according to a plan, which prescribes what information to collect, where it should be sought, and how it should be recorded. In the observational method, the researcher does not control any of the variables. In fact, it is important that the observation be carried out in such a manner that the investigations do not change the behaviour of what is being observed. Errors introduced as a result of observing a phenomenon are known as systematic errors because they apply to all observations. Once valid observations have been recorded, the researcher analyzes and interprets the data, and develops a theory or hypothesis, which explains the observations.

The experimental method begins with a hypothesis. An experiment is designed to test the hypothesis by observing the response of one variable to changes in a limited number of other variables under controlled conditions. The data are analysed to determine whether a relationship exists which either confirms or refutes the hypothesis. The experimental method is frequently used in investigations in the physical sciences and engineering. In both methods, establishing relationships may include the development of models to explain the relationships being postulated. Occasionally, the observational method may lead to a hypothesis, which is subsequently tested by the experimental method.

As with the observational method, it is important that the act of collecting the data not change the behaviour being recorded, but, unlike observations, there is usually some interaction between the researcher and the subjects being studied. Three types of surveys can be recognized: historic, current and prospective. Historic surveys collect data on how things were in the past with the intent of explaining certain phenomena. A current survey examines how things are now, such as attitudes to new traffic signs. A prospective survey



selects a group of people today and examines the same people at future times to investigate changes. Prospective surveys are often used in medical research, for example, to examine the incidence of cancer or heart disease in a segment of the population.

The terms theory and hypothesis are sometimes used interchangeably, but there is an important distinction between the terms. A hypothesis is an idea put forward to explain certain facts, and which can be tested. A theory is broader in scope and constitutes a conceptual framework that seeks to explain the connection of events and enables other relationships to be predicted. From a theory, it should be possible to derive testable hypotheses, which, if supported by the data, enhance the validity of the theory. Usually, many related hypotheses have to be tested and verified, before one has confidence in the validity of a theory. The connection between the data and the hypothesis is much stronger than between the data and the theory, which is conceptual and results from an intellectual process.



UNIT IV

CAUSAL CONNECTION

Introduction

The notion of cause is of great importance in science as well as in everyday life. The most general ideal of cause is about some phenomenon that produces and accounts of a change or changes. Everything that has a beginning must also have a cause to account for it. The connection between cause and effect is called causal connection. The term ‘causal’ refers to the formation or expression of a cause or causes. The principle of causality implies that everything has a cause or nothing comes out of nothing. Out of nothing, nothing can come. This has been expressed as ex nihilo nihil fit.

Nature of cause

Cause is the set of conditions necessary and sufficient to produce the effect. A condition is said to be necessary if in the absence of which the effect would not occur. For example, the statement ‘nutrition is necessary for the growth of a plant’ means that in the absence of nutrition the plant would not grow. A condition is said to be sufficient if it is such that whenever it is present, the effect occurs. To establish the causal relationship is the distinguishing mark of the scientific induction. Philosophers, logicians, and scientists have defined causation differently according to their requirements. Philosophers deal with the theme of causality which mainly attempts to answer the question about how or why events happen. The concept of causality is closely related to the problem of determinism and free will. Determinism states that strict causal laws govern all physical and natural events, and even human actions are governed by them.

Causal connection is a relation of invariable succession and hence stronger and stricter connection than merely correlation. Causal relationship implies succession in time. Cause is antecedent, and hence precedes the effect. Effect is consequent, and hence follows the cause. In time sequence, it is the cause which first and the effect later on. The time interval between cause and effect may be very less. Because of this a cause is different from co‐ existence. In the proposition “all crows are black” crow and black color co‐ exist. One is not the cause of other.

Though cause is antecedent event, but not every antecedent is the cause or part of the cause of an effect. If x is the cause of y, then certainly x precedes y, but to say that since p precedes q, therefore, p is definitely cause of q, is wrong. This kind of thinking leads to the fallacy of post hoc ,ergo propter hoc which means after this therefore the consequence.

Cause must be invariable as well as unconditional antecedent of an effect. Unconditionally of antecedent event means the antecedent is self – sufficient to produce an effect. The antecedent event when capable enough to give rise to effect by itself, then it is called unconditional, for it does not need anything more to give birth to effect. Besides



being unconditional and invariable, cause must also be immediate or proximate antecedent of an effect. Scientist and logicians are not interested in the remote causes. The conditions which precede cause and which have indirect bearing upon the effect are called “remote, mediate or predisposing causes”. For instance in the following case:

A is cause of B

B is cause of C

C is cause of D

D is cause of E

Therefore A is cause of E.

A is remote cause of E; B and C are also remote causes of E, though less remote than A. Only D is immediate or proximate cause of E. Logician and scientists are interested merely proximate causes. Cause, thus is defined as invariable, unconditional, immediate antecedent of an effect.

Ancient views of cause

The primitive notions of cause ascribe causation to some agency. In the anthropomorphic view, natural phenomena are regarded as caused and controlled by Gods and spirits conceived in terms of the human will to act. For instance, in the Vedic religion Varuna is the god of rain fall and Vayu is the power behind wind movement. Animism is another prehistoric view that explains natural phenomena as caused by some life force inherent in them. These ancient views are defective mainly because they emphasize the terms instead of the relation.

Aristotle’s view of cause

The influence of Aristotelian physics and account of scientific demonstration transformed discussions about causality, leading to more analytical treatment of the principle of causality and the achievability of scientific knowledge. Aristotle sought explanation of nature and change in causal principles. All things tend to intrinsically determined goals. Every change requires a cause, and nothing can change by itself. These assumptions adopted from his predecessors and taken as self‐evident led Aristotle to propose material, formal, final, and efficient causes (not necessarily all four) to account for change. The basic principles that influenced his medieval commentators attest to their acceptance generally of commonsense notions and of the principle of the uniformity of nature. Things acting always or for the most part in regular and predictable ways cannot, they thought, be due to chance. They contrasted natural motions with forced motions, and attempted to account for forced motions in terms of natural motions. Accordingly, they rejected the possibility that regularly observed events could be the result exclusively of external forces acting on a body.



Critics tried to refine notions and settle disputes about details. Most adopted Aristotle’s formal and final causes, the material subject of change that is receptive of form and capable of being formed, and the efficient or producing causes of change and motion. In some cases, entities transmit the form they possess to the entity that they produce or in which they produce a change. Among motions, locomotion has a privileged status. Because all change is dependent on contact or proximity, every change depends on locomotion. In Aristotle’s cosmological vision, lower motions depend on higher motions. In a chain of efficient causes, the first is the moving cause, leading Aristotle to propose the unmoved mover as the ultimate and first source of all change in the universe.

By his account no change is neutral; all change is either according to nature or contrary to nature. In Aristotle’s account of natural elemental motions, their natures account for tendencies and directionality, but their moving or efficient causes are the entity that generated the elemental nature in the first place and the agents that remove obstacles. The distinctions among the elements are rooted in qualitative contraries in the case of the contrary motions of sub lunar elements, and in the eternal circular motion of the celestial element, according to the Prime Mover’s emulation of the unmoved mover.

Aristotle introduced the earliest systematic expression of causation in the West. His four fold idea of cause is as follows:

The material cause‐ the matter or substance of which a thing is made.

The formal cause ‐the shape or form into which a thing is made.

The efficient cause – the agency that produces a thing, and

The final cause – the purpose or goal that determines the making or becoming of a thing. The material and formal causes are intrinsic as they are inherent in the effect. The efficient and final causes are extrinsic as they remain outside the effect.

Plurality theory of causation

The scientific interpretation of causation has important characteristics that the same cause produces the same effect. If there is the slightest change in the cause event, then effect event also changes accordingly. This scientific interpretation of causation that the same cause produces same effect however differs from the views held by certain logicians, like J. S. Mill who think there can be more than one cause which produces the same effect. There can be several causes, several logically independent sufficient conditions which produce the same effect. This theory is called plurality theory of causation. Many causes may produce mechanical motion; many causes may produce some kinds of sensation, many causes may produce the same effect, e.g, death.



The causes of unnatural death are several such as accident, illness, bullet injury, poison, burns, etc. The effect remains the same. Take another example; there are many sources of light say electricity, fire, moon, sun, etc. Take yet another example of poor cultivation of crops. The crops can fail due to various reasons. The flood can destroy the crops, the insects may damage it, the drought can spoil it, but the result is single, that is the crops had failed.

For a common man and on the level of common sense understanding the plurality theory of causation seems to be correct and acceptable. But if we analyze the situation a little further and go in depth, then the plurality theory of causation will be found incorrect and unattainable. In all examples cite above, the causes were analyzed and separated but effect events were not analyzed properly. The causes are labeled as C1, C2, C3, etc.. But effect event was wrongly presumed to be identical. We have wrongly thought effect is one and the same. Whenever there is slightest change in because event effect, event also changes. Death due to bullet injury is of different kind than the death of poisoning. If all the deaths would have been of the same kind, then why postmortem is done to determine the right cause of death.

The crops failed due to flood is of different kind than the crops failed due to insects, or lack of proper care. Similarly sunlight is different from moon light. Candle light is of a unique type, and different from the moon light. Candle light is of a unique type, and different from the rest of other types of lights. As the sources of light are different, nature of light is also different. Against the plurality theory of causation, the unique theory of causation (same cause produces same effect) appears to be more logical and consistent.

The unique theory of causation is also compatible with scientific interpretation of causation which is in terms of conditions. A set of certain conditions produces a certain effect, and the slightest variation in those conditions makes difference to the effect event.

The concept of cause as the set of certain conditions responsible for producing an effect, however, no longer fascinates a scientist. This conception of causation in terms of conditions is replaced by the latest concept of functional dependence. The word function is widely used in mathematics. In an effort to be more accurate and certain, the scientists express causal relationships in terms of mathematical equations. Consequently, scientific laws are formulated n mathematical terms and mathematical framework.

Scientific definition of cause (J.S. Mill definition) John Stuart Mill defines cause as “the invariable and unconditional or necessary antecedent”. Mill’s scientific definition of cause – effect relation implies the following: Cause is an invariable and unconditional antecedent of the effect Cause –effect relation is reciprocal or reversible Cause is the totality of conditions



Cause is quantitatively equal to effect.

i) Cause and effect are relative terms. Hence a cause is the antecedent phenomenon and the effect is the consequent. But it is not always a relation of before and after. In fact, there is no time gap between cause and effect as in the case of fire as the cause of heat. It is clear that fire and heat occur simultaneously even though the former is the cause of the latter. So causation implies the beginning of a phenomenon succeeded by another resulting phenomenon.

ii) Cause is the invariable antecedents of effect in the sense that the presence of the one implies the necessary occurrence of the other. So whenever the cause is present we expect the effect to follow and vice versa.

iii) An antecedent, to be cause must not only be invariable but also unconditional or necessary. So the relation between cause and effect is not mere conjunction, but an intrinsic connection. The occurrence of the invariable antecedent A becomes the causal condition of the effect B if and only if A can produce B independently of any other condition. Hence unconditional means ‘not dependent on any other condition’.

iv) implies that cause is a immediate antecedent. Whether other conditions are present or not, as soon as the cause is preset the effect must follow immediately from the cause. So nothing intervenes between the cause and its effect.

v) Reciprocity or reversibility is another characteristic of cause – effect relation. Hence the same cause must have the same effect, and the same effect must have the same cause. This follows from the Principle of Uniformity of Nature. So cause is reversible into effect and vice versa, and therefore we must be able to infer the effect from the cause and the cause from the effect.

vi) Cause is the totality of conditions. In fact, an effect follows from many circumstances that are necessary for its occurrence. The cause of an event is not always a single antecedent but a set of antecedents. Several conditions combine together to produce an effect. If anyone necessary condition is absent, the effect will not occur.

vii) Cause is quantitatively equal to the effect. According to the Law of Conservation of Matter and Energy, the total quantum of matter and energy in the universe remains constant. Hence causation implies transfer of energy from cause to effect without change in quantity. The quantity o f energy in the effect is exactly equal to that in the cause.

Mill’s method of Experimental Inquiry

The aim of inductive investigation is to establish universal laws, and causality is the most fundamental expression of these laws. J.S. Mill stated, “There is no other uniformity in the event of nature than that which arises from the law of causation”

Mill suggested five methods of experimental enquiry



The Method of Agreement The Method of Difference The Joint Method of Agreement and Difference The Method of Concomitant Variations The Method of Residues

The Method of Agreement

If two or more instances of the phenomenon under investigation have only one circumstance in common then, the circumstance in which alone the entire instance agrees is the cause or the effect of the given phenomenon.

Analysis of the rule: There should be several instance of the phenomenon under investigation. The instance must be positive i.e.; those in which phenomenon occurs. They have only one circumstance in common. The other circumstances are available. The invariable circumstance is the cause of the phenomenon.

Symbolic expression: ABC followed by PLM ADE followed by PQR AFG followed by PST Therefore A is the cause or the effect of P.

Example: Suppose we want to know the cause of malaria, we study a number of malarial patients; they differ in age, sex, food, strength and heredity. But all of them are invariably exposed to mosquito bite. Thus we conclude that mosquitoes are the cause of malaria.

Limitations

The method of agreement is mainly an observational method. This method takes into account only positive instances. It is difficult to fulfill this condition because natural events are extremely complex. Even if we are able to discover the single common circumstances in which all the instances agree, the conclusion is only probable and not certain.

This method helps us to discover the invariably of a single antecedent, but not the element of necessity, But mere invariability is not enough for causation.



The method of agreement is not much useful if we are presented with a plurality of causes. Mill explains the method as “if two or more instances of the phenomenon under investigation of have only one circumstance in common, the circumstance in which alone all the instances agree is the cause (or effect) of the given phenomenon.

The method of agreement is also called a method of observation. In this lie its merits as well as demerits. In the field where the experiments are very dangerous to perform, the method of observation is the only available method for the investigation of causal relationship. But sometimes the phenomenon occurs so rarely that one has to wait quite a long time to observe it again. It may possible that the phenomenon may occur once in hundred years. In that case the method of agreement is not profitable method for discovering causal connection.

Mill’s formulation of the method demands that cause and effect events should be analyzed into simpler components. By the method of agreement once cannot differentiate between cause and co existence. For instance day and night follow each other invariably but none of them is cause of another. They both are rather co effects of something else, similar objection can be made regarding heat and light, lightning and thunder.

Advantages

The method of agreement has all the advantages of observation. In this method, we can argue effect to cause and from cause to effect. Its main applications in suggesting hypotheses about cause.

The Method of Difference (disagreement)

If an instance in which the phenomenon under investigation occurs, and an instance in which it does not occur, have every circumstance in common save one, that one occurring only in the former; the circumstance in which alone the two instances differ, is the effect or the cause or an indispensable part of the cause, of the phenomenon. Mill stated as “if an instance in which the phenomenon under investigation occurs, and an instance in which it does not occur, have every circumstance save one in common, that one occurring only in the former, the circumstance in which alone the two instances differ, is the effect, or the cause, or a necessary part of the cause, of the phenomenon.

Analysis of the rule:

Positive and the other negative circumstance should be present in the positive instances and absent in the negative one This sole differing circumstance must be causally connected with the phenomenon.

Symbolic Expression ABC followed by PQR BC followed by QR



A is the cause or the effect or an indispensable part of the cause of P.

Examples:

A piece of litmus paper when dipped in acid turns red at once. Another exactly similar piece of litmus paper when dipped in water does not turn red. Therefore, acid is the cause of the color change in litmus paper.

In the Coin and Feather Experiment, we can prove that these two objects all on the ground at different times under normal circumstances. This is due to resistances of air. The cause of the difference in time can be analyzed in the following experiment:

Instance 1(positive)

In a jar filled with air a coin and feather are dropped from the same height at the same moment. They reach the bottom of the jar at different time t1 and t2.

Instance 2(negative) The same experiment is repeated after removing the air in the jar. The coin and feather reach the bottom of the jar at the same time t1.

So we can conclude that the resistance of the air in the jar is the cause of the difference between t1 and t2. This is called the method of difference because it is based on the difference between the two observed instances. It is an experimental method. If the experiment is performed with accuracy we arrive at the cause with certainty. Sometimes only one experiment is sufficient to establish the result.

This is called the method of difference because it is based on the difference between the two observed instances. It is an experimental method. If the experiment is performed with accuracy, we arrive at the cause with certainty. Sometimes only one experiment is sufficient to establish the result.

Limitations

This method is mainly an experiment method, we can reason only from cause to effect, but not vice versa. As in the method of agreement, in difference method also it is very difficult to reach a conclusion about the cause, in case there is a plurality of causal conditions.

The Joint Method of Agreement and Difference If two or more instances in which the phenomenon occurs have only one circumstances in common, while the two or more instances in which it does not occur nothing in common save the absence of that circumstance, the circumstance in which alone the two sets of instances differ, is the effect or the cause, or an indispensable part of the cause of the phenomenon. In the joint method the negative instances strengthen the conclusion drawn from the positive instances, thus in this method there is emphasis both on necessary and sufficient conditions.



Analysis of the rule:

In this method we require two sets of instances. In the first set of positive instances the single common circumstance is detected. If that single common circumstance present in the first set is found absent in the second set of negative instances that is the probable cause of the given phenomenon. The instances must be as far as possible from the same field.

The causal conclusion is based on the uniform presence of a condition in the positive set and its uniform absence in the negative set. The Joint Method is also called the double method of agreement because its conclusion is based on a double agreement, because its conclusion is based on a double agreement, i.e the agreement in presence and the agreement in absence.

Symbolic expression Positive set ABC followed by PQR ACD followed by PRS ADE followed By PST Negative set BCD followed by QRS CDE followed by RST DEF followed by QTV Therefore A is the cause of the effect or indispensable part of the cause of P.

Example We take the case of a person suffering from insomania. The circumstances proceeding the sleepless nights such as heavy meal, prolonged study, taking a cup of strong coffee, mental tension etc are analyzed carefully. The patient concludes that ‘taking coffee’ is the only invariable common circumstance present in all the instances of sleepless nights. By the method of agreement, he may consider this condition as the probable cause. In the next stage, the analysis is repeated by eliminating the common circumstance, that is, by avoiding coffee in the succeeding nights. If the patient is able to sleep well, he can further conclude that the condition present in all positive instances, and absent in all negative instances is the probable cause of his insomnia. Limitations In the joint method, we have to consider the only one circumstance that is commonly present in the positive instances and commonly absent in the negative instances. This is not much easy in a field of investigation.



This method, like the agreement and difference method we can suggest only the probable cause. Moreover, this method cannot help us to establish a quantitative relationship between cause and effect. Advantage This method combines the advantage of both the agreement and difference methods. If we are able to get true negative instances, then by eliminating all irrelevant conditions, this method can give us the cause of a phenomenon. Some logicians consider it as the fundamental method of science. It is largely used in various social sciences.

The Method of Concomitant Variations Whatever phenomenon varies in any manner, whenever another phenomenon varies in some particular manner, is either a cause or an effect of that phenomenon or is connected with it through some fact of causation. Analysis of the rule We take two phenomena that always vary together. The variations are uniform. They must be in the same direction, i.e; either in direct or I inverse proportion.

Symbolic Expression C1 U S1 C2 U S2 C3 U S3

The variations in C are followed by corresponding variation in S. Therefore C is causally connected with S. Examples there is variation in the time, size and strength of the tides whenever there is a variation in the phases of the moon. Therefore, there is a causal connection between the phases of the moon and the changes in tides. Increase of poverty in society shows a corresponding increase in crime. Therefore, they are causally connected.

Limitations The method of concomitant variations is used mainly as an auxiliary to other methods. Hence in experiment it is combined with the method of difference, and in observation with the method ofagreement. Another defect is that the two phenomena varying together may not be causally connected, but may be the co – effect of a common cause. If the concomitant variations are superficial the result of analysis will be misleading.



Advantages This method enables the scientist to discover not only causal relations but also quantitative relations. It may be used as an auxiliary of the method of difference in order to get more precise results.

The Method of Residues This method can be employed only at a late stage of causal investigation. Residue means remainder. Residual phenomenon means that part of a complex phenomenon which remains unexplained by the already known cause. This method deals with the unexplained remaining part of the phenomenon Analysis of the rule By applying the previous methods, we have explained the causal connection among parts of some complex phenomenon. One antecedent is left. This antecedent is the cause of the remainder. Symbolic expression ABC followed by PQR B is known to be the cause of Q C is known to be the cause of R Therefore A is the cause of P. Examples: We weigh a wagon filled with coal. Already we know the weight of the wagon without coal. If we subtract the weight of the wagon from that wagon filled with coal, then we get the weight of the coal. The discovery of Neptune illustrates the application of this method. The planet Uranus did not follow the orbit calculated in terms of the attraction of the sun. The only one possibility left (the residue factor) was the existence of an undiscovered planet pulling Uranus out of its calculated orbit. The hypothesis was later confirmed with the discovery of Neptune. Limitations This method is dependent on previous inductions. It can be used only at the final stage to explain the residual phenomenon. The entire antecedent and their consequences must be analyzed before applying residue method. The five methods are dependent on each other. They are all derived from the Law of Causation as the universal expression of the uniformity of nature. Reference books‐

I M Copy & Carl Cohen, Introduction to Logic, Prentice‐Hall of India, New Delhi



James Edwin Creighton, An Introductory Logic, Mac Millan Publishing Co.,Delhi

UNIT V

HYPOTHESIS

Introduction

The aim of science is to discover the laws of nature. It explains the phenomena under observation. The discovery of such laws of nature is a result of the normal working of our thought processor. In the daily life of our observation facts are carried on the



background of a purpose or a theory. Therefore, it is natural that the scientist observes facts. He explicitly formulates a theory regarding the law which binds the observed facts. A theory about the relations of observed fact is called a hypothesis. A hypothesis is a guess or a supposition. It is a provisional explanation of facts. A Hypothesis sometimes employed instead of a known law, asa premise in the deductive investigation of nature. Mill defined hypothesis as “ any supposition which we make (either without actual evidence, or on evidence avowedly insufficient) in order to endeavor to deduce from it conclusions in accordance with facts which are known to be real; under the idea that if the conclusions to which the hypothesis leads are known truths, the hypothesis itself either must be, or at least is likely to be, true.” The deduction of known truths from an hypothesis is its verification. when this has been accomplished in a good many cases, and there are no manifest failures, the hypothesis is often called a theory. This term is also used for the whole system of laws of a certain class of phenomena; it is called in astronomy as a ‘theory of the heavens.’ Between hypothesis and theory in the former sense no distinct line can be drawn; for the complete proof of any speculation may take a long time.

Nature of Hypothesis

A hypothesis is merely a tentative or provisional solution to a problem. It is not the real solution of the problem, (for which the hypothesis is constituted) till verified. A hypothesis is of fundamental importance for a proper and systematic scientific investigation. It points the direction in which the scientist should make observations and conduct experiments. By framing hypothesis the research is focused on specific points and the entire energy is used to gather the evidences in favor of the hypothesis. Random investigations are of no help and only an organized investigation is fruitful. Hypothesis defines the scope of a scientific inquiry and helps in saving time and efforts of the investigators. The hypothesis serves as the starting point in the rigorous scientific research and thus a hypothesis is assumed as a guide to scientific inquiry. All scientific investigators start with the formulations of hypotheses and stops with their verification and proof.

Suppose when I go back home and I find my son not reached home from school which he normally does by that time, I start guessing and making tentative explanations as to what would have happened to him. I may suppose that he has missed the school bus, or his school bus is late for it is caught in traffic. These alternative explanations, suggestions or solutions are called hypothesis.

A hypothesis is simply a suggestion or a possible explanation of a particular phenomenon. It is merely a suggestive, tentative or a provisional solution to a problem. Prof. Coffeey defines hypothesis as “a hypothesis is an attempt at explanation; a provisional supposition made in order to explain scientifically some fact or phenomenon”.

A hypothesis is extremely important in every field of investigation. Let us see how it is framed. The formation of a hypothesis is not a mechanical process. No rules or criteria can be laid down for making a “relevant” or “good” hypothesis. Actual framing of hypothesis is the work of a genius. Here the sagacity, genius and originality of a scientist play important role, for only a genius or trained mind can see something significant in the



phenomenon which others do not notice. Hypotheses are suggested, writes De Morgan, not by rules, but by sagacity of which no description can be given previously because the very owners of it do not act under any prescribed laws. S.H. Mellone adds beautifully, ‘nature, herself ….. dies gives broad hints as to the direction in which a fruitful hypothesis may be looked for, but only a prepared mind knows how to take the hint’.

Nature gives ‘broad hints’ to inquisitive mind and they are finger posts in nature pointing outlines of fruitful inquiry. Induction by simple enumeration and analogy are two main sources which suggest hypothesis to scientist. Two phenomena when repeatedly occur together, and then it suggests that there is some connection between them, and consequently a scientist frames a hypothesis. Induction by simple enumeration cannot prove the causal connection between two phenomena but it does suggest a hypothesis, a line of inquiry to a scientist. Similarly analogy does not conclusively prove a causal connection though it is a fruitful source for suggesting hypothesis. When it is found that two things resemble each other in certain important respects, we frame the hypothesis that they will possibly resemble each other I other respects too. The planets, earth and mars, resemble each other in possessing similar kind of atmosphere, land etc. On the basis of these resemblances we are led to suppose that the planet mars might resemble the earth in being inhabited by living creatures. The analogy is a very important source of making hypotheses.

Science demands a higher degree of exactness and in this sense scientific research is a vigorous investigation. For this purpose there should be well defined problems which need a solution. One of the important characteristic of scientific thinking and of all thinking having scientific spirit is to grasp the problem and its nature before proceeding to solve it. Sometimes it comes to a scientist well defined and some other times the scientist himself sees a problem where others do not. Only attentive and intellectually curious mind sees the problem where others do not. A scientist then begins by providing possible solutions, conjectures, suppositions, hypothesis to solve the marked problem. All his energy is then focused on framing and verifying hypotheses.

A hypothesis is considered for serious discussion only if it satisfies certain conditions, though these conditions are, by no means, conclusive or exhaustive. A Hypothesis is a guess or supposition, as to the existence of some facts or law which will serve to explain a fact or connection of facts already known to exist. It is an expression of the tendency of the mind to leave nothing standing in isolation, but to explain the various parts of the experience by bringing them into relation with one another. It is only the beginning of explanation. It is an attempt to explain facts and in this way either verified or disproved.

In ordinary experience, we are constantly trying to imagine the most lightly explanation of facts which we perceived through the sense. For ex; if a man has typhoid fever, we are sure to guess that the he has being drinking impure water. The formation of hypothesis is simply the minds to response to the demand for explanation. Theory is another word that is often used as equivalent to hypothesis. Strictly speaking it is better usage to employ the term hypothesis for the unverified or only partially verified guess, and



to reserve theory, for the hypothesis that has been more completely demonstrated. It is necessary to distinguish in some way the mere hypothesis, or supposition which is often as lightly to be false as true, from the hypothesis which has been established by proof. Hypothesis has been by a flash of scientific genius by imaginative insight which we may almost called inspiration that great scientific theories have discovered. Man of scientific insight penetrates more deeply is not the nature of things and is able to discover analogies and resemblances to which the ordinary man is blind. We are constantly making hypothesis of these character to explain the phenomena we meet within everyday experience. The popular use of hypothesis is opposed to the scientific usage of hypothesis, in the case of scientific hypothesis we assumes the explanation of the cause – effect relationship. A hypothesis is an attempt at explaining the cause of a new fact, it is tentative or probable explanation about the cause of an observed facts.

A fertile mind is necessary for making a good hypothesis. Good hypothesis are suggested by a flash of scientific genius, by imaginative insight. Observation of fact is another equally important requisite for the formation of a hypothesis. The mind must be richly stored without observed facts in order to renter the hypothesis worthy of consideration. Newton’s passage from a falling apple to the universal law of gravitation was an act of the prepared imaginations. At every stage of inductive reasoning hypothesis place am important role. All science starts with hypothesis. The story of induction is nothing but the story of hypothesis. The first stage of inductive reasoning is the observation of facts. The second stage of induction is the formulation of hypothesis out of observed facts. Verification of hypothesis is to test its correctness is the third stage of induction. The final stage of scientific induction is connected with hypothesis because the hypothesis which has been proved to be only adequate explanation of the given phenomena and established as a general law. Thus hypothesis is vitally connected with scientific induction.

Conditions of good hypothesis The main characteristic of a good, valid, and legitimate hypothesis is that it should explain facts around us; it must be based on events actually occurring in nature. Valid hypothesis depends on facts in its origin and also for its verification. A good hypothesis is that it should be verifiable with reference to observation or experience. The verifiability of a hypothesis can be done directly or indirectly. A hypothesis which lacks any verification is called barren hypothesis, and is not for the scientific inquiries.

A hypothesis should be purposeful, and directed to solve the problem for which it is framed. Random or irrelevant hypotheses cannot be considered for serious discussions in sciences or in ordinary common life. In other words, a hypothesis must be relevant to the problem it is supposed to solve. Relevance here means the hypothesis must either be a cause or part of a cause of a phenomenon for which it is formed. If, however, a hypothesis is neither or them, then it is irrelevant hypothesis and cannot be called ‘good’ hypothesis. The hypothesis must be clearly and distinctly conceivable in itself. It should be stated in the clearest terms. The vague, obscure and ambiguous hypothesis will only compound the problem of scientific instead of solving it.



A hypothesis which needs less calculation or mapping or observation is considered good. The scientist prefers the ‘mathematically simplest hypothesis’ equation if both fit the data. Copernicus suspected that complexities of the epicyclical orbits of the heavenly bodies were due to the observers own motion. By shifting to the sun as centre of the coordinate system, he managed to produce as far simpler system of celestial bodies.

One of the important characteristics of a goods hypothesis is that it must not contradict other established truths or laws. This condition requires that we should take into account the achievements of the past. Certain things have been established rather definitely and any novel suggestion, which contradicts one of such well established laws, will be treated with suspicion. Knowledge of facts and laws previously ascertained give steadiness to scientific knowledge and nay contradiction of these established laws will only raise the suspicion towards the new hypothesis. There are instances in the history of sciences, such as Ptolemy’s theory of universe (according to which the earth is the centre of the universe, and the sun, the moon and other planets revolve around it) was once established and accepted theory. It was later challenged and replaced by Copernican theory according to which sun is the centre of the solar system, and the earth, and other planets move around it.

A hypothesis which conforms to the various conditions laid down above is called valid, legitimate, good or working hypothesis. A working hypothesis is accepted as true for time being and is used as a guide for further inquiry. But a working hypothesis is accepted as the real solution only after verification and confirmation. It is to remember that a valid scientific hypothesis shall be conceivable and not absurd. The hypothesis shall not be contradict any of the known laws of nature .The hypothesis must be based on facts, and the hypothesis must be verifiable.

The verification of the hypothesis is the most essential test of the soundness of a hypothesis. A hypothesis from which nothing can be deduced or inferred as consequences is known as Barren hypothesis. A barren hypothesis is incapable of verification it does not admit of any deductions from it. For example; the failure of monsoons is due to anger of god, and the fever of the child is due to the evil eye sight by the neighbors.

Verification and Proof of Hypothesis

A working hypothesis is to be tested and verified. Without verification a hypothesis can never be accepted as the real solution to the problem. This is the most crucial stage in the scientific investigation. There are two stages of testing the validity of a hypothesis.

1. Verification of a hypothesis

2. Proof of a hypothesis



Verification of a hypothesis means testing of the truth of the hypothesis in the light of the actual facts and in the context of empirical data. The process of verification involves a comparison between the conclusion deduced from the hypothesis and facts gathered through observation. The greater the agreement between the inferences derived from the hypothesis and facts gathered through of confirming the hypothesis. Verification means to find out whether the conclusion derived from the hypothesis is supported by the actual experiences or not. Verification of a hypothesis is of two types. They are direct and indirect.

(a) Direct Verification

It is done by direct appeal to experiences and observation. Suppose one wants to test the hypothesis that the involvement of students in the college administration solves the discipline problem among the students. For this the behavior of the students are studies to find out whether they respond to the responsibility given to them. If the observation shows that an increased participation in the college administration decreases the indiscipline among them, then the hypothesis is verified by direct observation.

(b)Indirect verification

In many cases direct verification of hypotheses is not possible, in those cases indirect verification, and indirect verification and indirect evidence are looked for to verify the hypotheses. In indirect verification the consequences are deduced from the hypothesis (the one which one wants to verify) and they are then compared with the actual facts. If the deduced consequences or evidences agree with the facts actually observed, then the hypothesis is verified, otherwise it stands rejected.

There are situations in science where a scientist verifies the hypothesis indirectly, that is, by deducing evidences, such as the hypothesis of universal gravitation, or the atomic hypothesis, or the gene theory of biology than by deducing from it directly testable consequences. Indirect verification of a hypothesis is done by constructing a logical argument. If expressed in the strict logical form it becomes a hypothetical syllogism. Suppose one wants indirect verification of a hypothesis say H, then one will frame hypothetical syllogism as follows: If the fact S is observed, then the hypothesis H is true. S is observed. Therefore, the hypothesis H is true. Take a concrete example: If the roads are wet, then it has rained recently. The roads are wet. Therefore, it has rained recently. Take another example: If the house is badly ransacked then the aim of criminals was to steal.



The house was badly ransacked. Therefore, the aim of criminals was to steal.

In all the above examples the hypotheses are verified or confirmed on the basis of certain other facts which are observed as true.

The hypothetical syllogism can also be used to disconfirm or to disprove a rival hypothesis say H. The structure of the reasoning adopted for this purpose would be as follows:

If hypothesis H is true, then the fact S must be observed. The fact S is not observed. Therefore, the hypothesis H is not true. Yet another example, If it rained recently, then the rods are wet. The roads are not wet. Therefore, it did not rain recently. Take another illustration: If the aim of criminals is to rob, then the valuables must be missing. But no valuables were missing. Therefore the aim of criminals was not to rob.

It is evident that by disproving the rival hypotheses to increase the probability of some other hypothesis. For example, in order to know by the cause of the gruesome crime in which all the members of the family were killed, the investigating team makes a number of hypotheses say H1, H2, H3 etc. By framing the hypothetical syllogism the rivalry hypotheses are eliminated one by one. If the investigating team wants to know whether the hypotheses H1 that is robbery was the motive of the crime, then by structuring hypothetical syllogism, as we have done above, H1 can to be ruled out. The investigating team then takes second hypothesis H2 for verification. The hypotheses H2 states that probably the revenge was the cause of the crime. The hypothetical argument is framed as follows:

If revenge was the cause of the crime, then the victims were known to be unpopular or unfriendly people.

But the victims were not known to be unpopular or unfriendly people.

Therefore, the revenge was not the possible motive of crime.

In this manner the hypotheses H2 is also disproved and eliminated. The list of hypotheses is short – listed in this way and then the attention is paid to the remaining possible causes of the crime.



Scientist detectives and historians use direct as well as the indirect verification to justify and verify their hypotheses. The utilitarian justification of a method of accepting and rejecting hypotheses is usually employed by them. The utilitarian justification of hypothesis means the satisfaction produced by accepting a particular hypothesis. If we get good result and it work pragmatically well in our experiences and explain the facts perfectly well, then the hypothesis is accepted as confirmed and verified. But no hypothesis is totally true or completely confirmed. There can be only a high degree of confirmation.

Proof of a hypothesis

Verification is merely one step in the direction of proving a hypothesis. The hypothesis is called proved conclusively only when it stands as the only hypothesis, providing an adequate explanation for the facts or is the only solution for the problem. In verifying hypotheses, the scientists take each alternative hypothesis one by one, and examine it in the light of available evidences. While verification is the process of evaluating each hypothesis separately on its own merits, proof is the process of comparison among the verified hypothesis. Proof of a hypothesis means a “process of elimination of competing hypothesis”. After eliminating rivalry hypothesis, the best and most acceptable hypothesis is chosen as the proved hypothesis. Hypothesis is first verified and then among verified hypothesis the best one is selected, and that chosen one is called proved hypothesis. When more than one hypothesis is verified then there is competition among them. I order to select one out of them, further investigation is done and then the best among them is chosen. This best chosen one is called proved hypothesis.

A proved hypothesis must adequately explain all the facts for which it has been made and it must be the only hypothesis to do so. Moreover, a proved hypothesis must explain not only those facts for which it is framed but other related facts also. For example, the law of gravitation explains not only the falling of bodies on the earth but provides the explanation for the movements of the planets and their behavior. In short, a proved hypothesis must be verified, and it must be adequate to explain the phenomenon under investigation, and also it should be the only hypothesis to do so.

In science, many hypotheses remain unproved even though they have been verified. This happens because the conclusive evidences may not be available to support the facts. For instance, there are different hypothesis regarding the origin of the world. Each one of them stands verified to some extent, but some has yet been proved conclusively. The demand for absolute and conclusive proof of a hypothesis is an ideal demand which cannot be always met. However, the very hypothesis that stands verified with the support of evidences is raised to the status of theory. At the same time a well approved and generally accepted theory becomes a law.

Reference Books

Same as in the unit 4



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Essentials of Material Logic - University of Calicut

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