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55Leibniz on Mind, Leibniz on Mind, Knowledge, and Knowledge, and

IdeasIdeas

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Bibliographical ResourcesBibliographical Resources (reminder): (reminder):

Descartes’ Descartes’ MeditationsMeditations free at: free at:

http://www.earlymoderntexts.com/http://www.earlymoderntexts.com/f_descarte.htmlf_descarte.html

Leibniz’s Leibniz’s Nouveau Essays Nouveau Essays free at:free at:

http://www.earlymoderntexts.com/http://www.earlymoderntexts.com/f_leibniz.htmlf_leibniz.html

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On/by ChomskyOn/by Chomsky::

Chomsky N. (2000). Chomsky N. (2000). New Horizons in New Horizons in the Study of Language and Mindthe Study of Language and Mind. . Cambridge UP: CambridgeCambridge UP: Cambridge

McGilvray J. (1999). McGilvray J. (1999). Chomsky: Chomsky: Language, Mind, and PoliticsLanguage, Mind, and Politics. . Polity Polity Press: CambridgePress: Cambridge

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Critique of LockeCritique of Locke

The The New Essays on Human New Essays on Human UnderstandingUnderstanding is an explicit critique of is an explicit critique of Locke who fails to recognize that the Locke who fails to recognize that the principle of necessary truths are latent in principle of necessary truths are latent in our mind.our mind.

Locke: matter may think.Locke: matter may think.

The main purpose of the The main purpose of the EssaysEssays is to is to vindicate the immateriality of the human vindicate the immateriality of the human soul/mind.soul/mind.

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Leibniz’s anti-materialismLeibniz’s anti-materialism

Materialism is the view that everything Materialism is the view that everything that exists is material, or physical.that exists is material, or physical.

In short, mental states and processes are In short, mental states and processes are either identical to, or realized by, physical either identical to, or realized by, physical states and processes. states and processes.

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The realms of the mental and the physical, The realms of the mental and the physical, for Leibniz, form two distinct realms.for Leibniz, form two distinct realms.

This, though, doesn’t entail, for Leibniz, This, though, doesn’t entail, for Leibniz, dualism. That is, the existence of both dualism. That is, the existence of both thinking substance and extended substance thinking substance and extended substance ((vs.vs. Descartes) Descartes)..

Leibniz opposes both materialism and Leibniz opposes both materialism and dualism. dualism.

He proposes a new view about the He proposes a new view about the relationship between thought and matter.relationship between thought and matter.

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If the human mind were identical to the If the human mind were identical to the brain it would be difficult, if not impossible, brain it would be difficult, if not impossible, to maintain that it is a mirror of God to maintain that it is a mirror of God (remember: monades are mirrors of God).(remember: monades are mirrors of God).

The immateriality of the soul/mind also The immateriality of the soul/mind also offers a good foundation for the Christian offers a good foundation for the Christian doctrine of the immateriality of the soul doctrine of the immateriality of the soul and thus of personal immortality. The body and thus of personal immortality. The body decomposes, while the soul survives.decomposes, while the soul survives.

We should remember that back in We should remember that back in Descartes’ and Leibniz’s time science Descartes’ and Leibniz’s time science wasn’t secular.wasn’t secular.

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Most of Leibniz's arguments against Most of Leibniz's arguments against materialism are directly aimed at the thesis materialism are directly aimed at the thesis that perception and consciousness can be that perception and consciousness can be given mechanical (i.e. physical) given mechanical (i.e. physical) explanation. explanation.

Leibniz’s viewpoint is that perception and Leibniz’s viewpoint is that perception and consciousness cannot possibly be explained consciousness cannot possibly be explained mechanically (remember that the science of mechanically (remember that the science of the time was mechanism).the time was mechanism).

Therefore, perception and consciousness Therefore, perception and consciousness cannot be physical processes.cannot be physical processes.

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Perception and what depends upon it is Perception and what depends upon it is inexplicable on mechanical principles, that is, inexplicable on mechanical principles, that is, by figures and motions.by figures and motions.

(In a clock we find parts pushing one another, (In a clock we find parts pushing one another, we don’t find perception, conscious states, we don’t find perception, conscious states, thoughts, …)thoughts, …)

Therefore it is in the simple substance Therefore it is in the simple substance (monade), and not in the composite or in the (monade), and not in the composite or in the machine, that one must look for perception.machine, that one must look for perception.

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The Mill ArgumentThe Mill Argument GoalGoal: to prove the : to prove the immaterialityimmateriality of the soul. of the soul.

Everyone must admit that Everyone must admit that perceptionperception, and everything , and everything that depend on it, is that depend on it, is inexplicable by mechanical inexplicable by mechanical principlesprinciples, by shape and motion, that is, imagine there , by shape and motion, that is, imagine there were a machine which by its structure produced thought, were a machine which by its structure produced thought, feelings, and perception. We can imagine it as being feelings, and perception. We can imagine it as being enlarged while maintaining the same relative enlarged while maintaining the same relative proportions … When we went in we would find nothing proportions … When we went in we would find nothing but pieces which push one against the other, and but pieces which push one against the other, and never never anything to account for perceptionanything to account for perception. Therefore . Therefore we we must look for it in the simple substance and not in must look for it in the simple substance and not in the composite, or in a machinethe composite, or in a machine. (. (MonadologyMonadology WF WF 270)270)

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The mill argument can be dismiss on the The mill argument can be dismiss on the ground that it overlooks the fact that we may ground that it overlooks the fact that we may lack the understanding or knowledge to see lack the understanding or knowledge to see consciousness present in the machine. We’re consciousness present in the machine. We’re incapable of coming out with: “Look, a thought incapable of coming out with: “Look, a thought over there”. Yet, there may be a thought …over there”. Yet, there may be a thought …

The argument is best understood in focusing The argument is best understood in focusing on the notion of on the notion of explanationexplanation, i.e. there is , i.e. there is something about mental life that mechanism something about mental life that mechanism cannot explain.cannot explain.

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The limits of a mechanistic The limits of a mechanistic explanationexplanation

The unity of consciousnessThe unity of consciousness cannot be cannot be explained invoking mechanistic principles explained invoking mechanistic principles (our mental life is not compartmentalized). (our mental life is not compartmentalized).

E.g.: clockwork machinery could never E.g.: clockwork machinery could never explain time-keeping. Water molecules explain time-keeping. Water molecules could never explain liquidity. could never explain liquidity.

There are different levels of explanation There are different levels of explanation which may not reduce one to the other.which may not reduce one to the other.

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Leibniz is Leibniz is notnot offering offering an argument an argument from ignorancefrom ignorance..

He’s not making the fallacious inference: He’s not making the fallacious inference:

since we can find no explanation in the since we can find no explanation in the machine, machine,

then no explanation could be given.then no explanation could be given.

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The machinery could never, in principle, The machinery could never, in principle, explain the unity of consciousness.explain the unity of consciousness.

This is a basic premise of the argument This is a basic premise of the argument against materialism.against materialism.

The direct experience of ourselves is the The direct experience of ourselves is the only direct experience we have of only direct experience we have of substantial unitysubstantial unity..

By means of the soul there is a true unity By means of the soul there is a true unity which corresponds to what is called which corresponds to what is called the the II in in usus; This ; This II could not occur in artificial could not occur in artificial machines, nor in the simple mass of matter, machines, nor in the simple mass of matter, however organized it may be. however organized it may be.

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The human mind being a simple and immaterial The human mind being a simple and immaterial substance is also naturally substance is also naturally immortalimmortal. .

The immortality of the mind follows from its The immortality of the mind follows from its simplicity.simplicity.

no composition = no destruction; no composition = no destruction;

destruction = decompositiondestruction = decomposition

Monads can only be created or destructed by Monads can only be created or destructed by God.God.

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True immortalityTrue immortality (the personal immortality (the personal immortality relevant for ethics) involves also memory and relevant for ethics) involves also memory and self-consciousness (apperception). Only spirits self-consciousness (apperception). Only spirits have this property. have this property.

The morality of human minds depends on them The morality of human minds depends on them possessing memory and self-consciousness (for possessing memory and self-consciousness (for this reason they can be rewarded/punished).this reason they can be rewarded/punished).

Importance of memory for Importance of memory for personal identitypersonal identity..

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Critique of DescartesCritique of Descartes The cogito argument is a sophismThe cogito argument is a sophism. .

There can be no valid inference from a There can be no valid inference from a state of subjective uncertainty (Descartes’ state of subjective uncertainty (Descartes’ doubt) to what is objectively the case. doubt) to what is objectively the case.

It is not valid to reason: “I can assume or imagine It is not valid to reason: “I can assume or imagine that no corporeal body exists, but I cannot that no corporeal body exists, but I cannot imagine that I do not exist or do not think. imagine that I do not exist or do not think. Therefore I am not corporeal, nor is though a Therefore I am not corporeal, nor is though a modification of the body”. (“Critical Comments of modification of the body”. (“Critical Comments of Descartes Principle of Philosophy” 1691: L385)Descartes Principle of Philosophy” 1691: L385)

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The Mind-Body ProblemThe Mind-Body Problem

Leibniz's rejection of materialist Leibniz's rejection of materialist conceptions of the mind was coupled with conceptions of the mind was coupled with a strong opposition to dualistic views a strong opposition to dualistic views concerning the relationship between mind concerning the relationship between mind and body.and body.

Leibniz criticizes Descartes’ system Leibniz criticizes Descartes’ system because it doesn’t explain how the soul because it doesn’t explain how the soul can influence the body; how the mind can influence the body; how the mind unites with the body.unites with the body.

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Leibniz's opposition to Cartesian dualism Leibniz's opposition to Cartesian dualism stems not from a rejection of unextended stems not from a rejection of unextended substances, but from his denial of the substances, but from his denial of the existence of genuine extended material existence of genuine extended material substances. substances.

To begin with, Leibniz held the Scholastic To begin with, Leibniz held the Scholastic thesis that thesis that “being” and “one” are “being” and “one” are equivalentequivalent (the unity of substances). (the unity of substances).

Remember that Leibniz rejects the Cartesian Remember that Leibniz rejects the Cartesian notion of extended substance on the ground notion of extended substance on the ground that it lacks unity (extended bodies are that it lacks unity (extended bodies are aggregates and, as such, lack unity).aggregates and, as such, lack unity).

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Pre-established harmonyPre-established harmony

The human mind and its body have been The human mind and its body have been programmed by God in such a way that they programmed by God in such a way that they appearappear to interact causally with one another. to interact causally with one another.

There is a There is a constant conjunctionconstant conjunction. This lead . This lead philosophers to falsely believe that there is philosophers to falsely believe that there is actual causality.actual causality.

This is the denial of the mind/body This is the denial of the mind/body interaction.interaction.

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The Cartesian mind-body problem rests on The Cartesian mind-body problem rests on the assumption that both the mind and the the assumption that both the mind and the body are substances.body are substances.

Leibniz doesn’t endorse this because, Leibniz doesn’t endorse this because, properly speaking, human bodies are not properly speaking, human bodies are not substances (they are aggregates lacking substances (they are aggregates lacking unity).unity).

The human body, taken in abstraction from The human body, taken in abstraction from the mind, is never considered by Leibniz to the mind, is never considered by Leibniz to be a substance (cf. Leibniz idealism).be a substance (cf. Leibniz idealism).

The human body is an aggregate, thus a The human body is an aggregate, thus a phenomenon. As such it is not a substance.phenomenon. As such it is not a substance.

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In his later philosophy Leibniz holds that In his later philosophy Leibniz holds that the human body is grounded in immaterial the human body is grounded in immaterial souls or monads, but it is not itself souls or monads, but it is not itself immaterial.immaterial.

So Leibniz may face a problem in So Leibniz may face a problem in understanding the mind-body union.understanding the mind-body union.

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The doctrine of pre-established harmony The doctrine of pre-established harmony has been introduced as a thesis has been introduced as a thesis concerning the interaction between concerning the interaction between substances (i.e. the windowless monads).substances (i.e. the windowless monads).

Thus if pre-established harmony is used to Thus if pre-established harmony is used to solve the mind-body union, the body solve the mind-body union, the body should be, contrary to what Leibniz says, should be, contrary to what Leibniz says, a substance.a substance.

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Given that pre-established harmony holds among Given that pre-established harmony holds among substances, we cannot validly infer that the mind substances, we cannot validly infer that the mind is in harmony with the body, for the latter is not a is in harmony with the body, for the latter is not a substance. substance.

We would commit the We would commit the fallacy of compositionfallacy of composition..

We cannot infer from (i) what is true of the items We cannot infer from (i) what is true of the items in a group to (ii) what is true of the group as a in a group to (ii) what is true of the group as a whole.whole.

E.g.: It would be like inferring that since Jane E.g.: It would be like inferring that since Jane loves all the students in a school she loves the loves all the students in a school she loves the school.school.

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The doctrine of the pre-established harmony The doctrine of the pre-established harmony could be used within Descartes’ ontology where could be used within Descartes’ ontology where both the mind and the body are substances.both the mind and the body are substances.

Leibniz consider the world as consisting Leibniz consider the world as consisting merely merely of one of one typetype of substance of substance, though, there are , though, there are infinitely many substances of that type. infinitely many substances of that type.

These substances are partless, unextended These substances are partless, unextended entities, some of which are endowed with entities, some of which are endowed with thought and consciousness, while others found thought and consciousness, while others found the phenomenality of the corporeal world the phenomenality of the corporeal world (Leibniz’s idealism).(Leibniz’s idealism).

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Since Leibniz held that there is only one Since Leibniz held that there is only one type of substance in the world, the mind type of substance in the world, the mind and the body are ultimately composed of and the body are ultimately composed of the same kind of substance.the same kind of substance.

Yet, he also held that mind and body are Yet, he also held that mind and body are metaphysically distinctmetaphysically distinct..

For any person For any person PP, , PP's mind is a distinct 's mind is a distinct substance (a soul) from substance (a soul) from PP's body.'s body.

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The human mind and body are The human mind and body are causally causally insulatedinsulated from one another.from one another.

Each of our mental states is caused by a Each of our mental states is caused by a prior state of our mind and each state of our prior state of our mind and each state of our body is caused by a prior physical state.body is caused by a prior physical state.

Mind/body relationMind/body relation

The mind “expresses” its body by perceiving The mind “expresses” its body by perceiving it (perception is a species of expression).it (perception is a species of expression).

VsVs. Descartes, we have . Descartes, we have unconscious unconscious perceptionsperceptions..

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Mind and LanguageMind and Language

Leibniz, like contemporary cognitive Leibniz, like contemporary cognitive scientists, saw an intimate connection scientists, saw an intimate connection between the form and content of language, between the form and content of language, and the operations of the mind. and the operations of the mind.

really believe that really believe that languages are the best mirror languages are the best mirror of the human mind, and that a precise analysis of the human mind, and that a precise analysis of the signification of words would tell us more of the signification of words would tell us more than anything else about the operations of the than anything else about the operations of the understandingunderstanding ( (Nouveau EssaysNouveau Essays, ch.7, sec.6). , ch.7, sec.6).

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This view led Leibniz's to formulate a plan for a This view led Leibniz's to formulate a plan for a ““universal languageuniversal language”. I.e., an artificial language ”. I.e., an artificial language composed of symbols, which would stand for composed of symbols, which would stand for concepts or ideas, and logical rules for their valid concepts or ideas, and logical rules for their valid manipulation. manipulation.

He believed that such a language would perfectly He believed that such a language would perfectly mirror the processes of intelligible human mirror the processes of intelligible human reasoning. reasoning.

Leibniz came close to anticipating artificial Leibniz came close to anticipating artificial intelligence.intelligence.

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Natural languageNatural language

Despite its powerful resources for Despite its powerful resources for communication, it often makes reasoning communication, it often makes reasoning obscure since it is an imperfect mirror of obscure since it is an imperfect mirror of intelligible thoughts.intelligible thoughts.

According to this view, cognition is According to this view, cognition is essentially symbolic: it takes place in a essentially symbolic: it takes place in a system of representations which possesses system of representations which possesses language-like structure:language-like structure:

all human reasoningall human reasoning uses certain signs or uses certain signs or characters.characters. ( (On the Universal Science: On the Universal Science: CharacteristicCharacteristic; G VII, 204 (S, 17)); G VII, 204 (S, 17))

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Nativism: Innate IdeasNativism: Innate Ideas Main argumentMain argument for nativism: the human for nativism: the human

mind is causally independent from any mind is causally independent from any other substance except God.other substance except God.

This argument is a renewal of the Platonic This argument is a renewal of the Platonic and Cartesian doctrine.and Cartesian doctrine.

Like in Plato’s system, innate ideas should Like in Plato’s system, innate ideas should solve problems in the philosophy of solve problems in the philosophy of mathematics. E.g. to explain how mathematics. E.g. to explain how a priori a priori knowledge is possible (cf. Socrates knowledge is possible (cf. Socrates majeutics).majeutics).

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““idea”idea”

To be understood in a To be understood in a dispositionaldispositional way. way.

This contrasts Descartes’ threefold This contrasts Descartes’ threefold conception. In particular, the material conception. In particular, the material condition of ideas (i.e. ideas as acts).condition of ideas (i.e. ideas as acts).

To have an idea of To have an idea of aa is to have a mental is to have a mental disposition to think of disposition to think of aa when the right when the right circumstances occur.circumstances occur.

This contrasts with the act of thinking (e.g.: This contrasts with the act of thinking (e.g.: Descartes’ material condition). Descartes’ material condition). A disposition A disposition is not an actis not an act..

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Objects of ideasObjects of ideas, i.e. the semantics of ideas., i.e. the semantics of ideas.

Ideas necessarily take Ideas necessarily take possible entitiespossible entities as as their objects.their objects.

An idea must be about a An idea must be about a possible objectspossible objects. .

Thus from the fact that I can think of the Thus from the fact that I can think of the round-square it doesn’t follow that I have an round-square it doesn’t follow that I have an idea of it. For a round-square is an idea of it. For a round-square is an imimpossible object.possible object.

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An idea in one’s mind/soul is simply An idea in one’s mind/soul is simply another property of that monad. another property of that monad.

This happens according to an entirely This happens according to an entirely internal explanation represented by the internal explanation represented by the complete concept.complete concept.

But at the phenomenal level, it is no doubt But at the phenomenal level, it is no doubt the case that ideas are represented as the case that ideas are represented as arriving through one’s senses.arriving through one’s senses.

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3 levels of reality3 levels of reality

1. 1. Metaphysical level (it includes only Metaphysical level (it includes only monads with monads with their perception and their perception and appetition: no causality, no appetition: no causality, no space, no time).space, no time).

2. 2. Phenomenal or descriptive level (what Phenomenal or descriptive level (what appears to appears to be happening from the finite, be happening from the finite, imperfect perspective imperfect perspective of the human mind).of the human mind).

3. 3. Object of science (it is an illusion but in Object of science (it is an illusion but in which which nothing happens that is not based nothing happens that is not based on what really on what really happens in the metaphysical happens in the metaphysical sphere).sphere).

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Leibniz’s notion of ideas allows him to criticize Leibniz’s notion of ideas allows him to criticize Descartes’ ontological argument.Descartes’ ontological argument.

God exists if he is possible (God as the object of God exists if he is possible (God as the object of an idea is a possible object). It is thus a Divine an idea is a possible object). It is thus a Divine privilege to need only its possibility to actually privilege to need only its possibility to actually exist. exist.

Descartes’ argument is vitiated by the Descartes’ argument is vitiated by the assumption that we have an idea of God in assumption that we have an idea of God in Leibniz’s sense, i.e. as a disposition (and that Leibniz’s sense, i.e. as a disposition (and that Descartes builds God’s existence into the idea Descartes builds God’s existence into the idea itself). itself).

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Metaphysical argument for Metaphysical argument for nativismnativism

ArgumentArgument::

Pre-established harmony: the human mind Pre-established harmony: the human mind with all other substances is causally self-with all other substances is causally self-sufficient.sufficient.

From this + Leibniz’s theory of ideas, we From this + Leibniz’s theory of ideas, we should prove the innateness of all ideas.should prove the innateness of all ideas.

This is reminiscent of Descartes This is reminiscent of Descartes reply to a reply to a certain Broadsheetcertain Broadsheet: nothing reaches our : nothing reaches our mind from external objects …mind from external objects …

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What the argument proves is that nothing What the argument proves is that nothing reaches the mind from outside.reaches the mind from outside.

Does this prove that ideas are innate?Does this prove that ideas are innate?

(i) Ideas are disposition and (i) Ideas are disposition and

(ii) Dispositions are mental (ii) Dispositions are mental states.states.

Thus: Thus: (iii) since mental states (iii) since mental states cannot be externally cannot be externally caused, caused, no idea is externally caused.no idea is externally caused.

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The introspection argument The introspection argument for innate ideasfor innate ideas

Leibniz claims that if (as Locke concedes) we Leibniz claims that if (as Locke concedes) we assume that some ideas can be acquired from assume that some ideas can be acquired from reflection (introspection), then these ideas reflection (introspection), then these ideas must be innate.must be innate.

Two criticismsTwo criticisms of this argument of this argument

11. . This only proves that an idea is not This only proves that an idea is not sensory- sensory- dependent in its origins: it could be dependent in its origins: it could be formed with formed with the formation of the mind (it the formation of the mind (it rests on what we rests on what we mean by “innate”).mean by “innate”).

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22.. It merely proves that metaphysical ideas It merely proves that metaphysical ideas (substance, (substance, motion, …) are innate. It doesn’t motion, …) are innate. It doesn’t prove that prove that mathematical ideas are innate mathematical ideas are innate since we don’t reach since we don’t reach them by introspection. them by introspection. And mathematical ideas play And mathematical ideas play a central role in a central role in Descartes and Leibniz …. Descartes and Leibniz ….

This critique is a good one. The first can be This critique is a good one. The first can be answered. answered.

Answer to critique 1Answer to critique 1

The notion of reflection can be clarified in such a The notion of reflection can be clarified in such a way that what happens in post-natal acts of way that what happens in post-natal acts of reflection is that the mind first come to reflection is that the mind first come to conscious awareness of an idea that has always conscious awareness of an idea that has always been there.been there.

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Nativism: the argument Nativism: the argument from knowledgefrom knowledge

Like Plato in the Like Plato in the MenoMeno, Leibniz thinks that we , Leibniz thinks that we can argue for the innateness of geometrical ideas can argue for the innateness of geometrical ideas because of our capacity to know necessary because of our capacity to know necessary truths.truths.

See Socrates’ maieutic (the philosopher like a See Socrates’ maieutic (the philosopher like a midwife).midwife).

Leibniz doesn’t accept, though, Plato’s theory of Leibniz doesn’t accept, though, Plato’s theory of reminiscence, i.e. that we remember ideas/forms reminiscence, i.e. that we remember ideas/forms from a previous life.from a previous life.

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Plato’s argument proves only a dispositional Plato’s argument proves only a dispositional or virtual form of nativism.or virtual form of nativism.

In mathematics we make knowledge claims In mathematics we make knowledge claims that that it is necessarily true that p. it is necessarily true that p. E.g.: it is E.g.: it is necessary true that 2+ 2 = 4.necessary true that 2+ 2 = 4.

Claims of universal necessary knowledge Claims of universal necessary knowledge cannot be justified by appealing to sensory cannot be justified by appealing to sensory evidence.evidence.

Senses can give only instances of truth. They Senses can give only instances of truth. They cannot guarantee that what happens will cannot guarantee that what happens will always happen. Senses are linked to actuality always happen. Senses are linked to actuality ……

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Innate principle play a Innate principle play a normative rolenormative role, , not an explanatory one.not an explanatory one.

Why innate principles must be true?Why innate principles must be true? Why they’re not a bunch of lies?Why they’re not a bunch of lies?

Descartes can answer in appealing to Descartes can answer in appealing to God’s benevolence: God is not a deceiver.God’s benevolence: God is not a deceiver.

Leibniz cannot answer this way since he Leibniz cannot answer this way since he dismisses Descartes’ appeal to God in dismisses Descartes’ appeal to God in order to solve epistemological problems.order to solve epistemological problems.

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Leibniz’s answerLeibniz’s answer

Our mind is a mirror of God.Our mind is a mirror of God.

Our innate beliefs have the same structure Our innate beliefs have the same structure as the eternal truths in the Divine mind.as the eternal truths in the Divine mind.

Unlike Descartes who appeals to God’s Unlike Descartes who appeals to God’s benevolence, Leibniz appeals to the benevolence, Leibniz appeals to the isomorphism between our min and isomorphism between our min and God’s mindGod’s mind (monads are the mirror of (monads are the mirror of God).God).

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Locke and Malebranche’s Locke and Malebranche’s challengechallenge

They both, from different perspectives, They both, from different perspectives, challenge Leibniz’s view that the mind is self-challenge Leibniz’s view that the mind is self-contained, a self-sufficient entity.contained, a self-sufficient entity.

LockeLocke (book 1 of (book 1 of EssaysEssays))

It is not clear what the nativists are It is not clear what the nativists are defending. Either: defending. Either:

(i) (i) the view that the existence of actual the view that the existence of actual knowledge and knowledge and concept-possession is concept-possession is innate or innate or (ii) (ii) that the mind is born with the potential that the mind is born with the potential to acquire to acquire such knowledge and concepts.such knowledge and concepts.

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1.1. If nativists assume (i) they are If nativists assume (i) they are asserting something asserting something empiricallyempirically falsefalse..

New-born babies show no sign of actual New-born babies show no sign of actual knowledge of necessary truths; they don’t knowledge of necessary truths; they don’t know the truths of logic and mathematics.know the truths of logic and mathematics.

2.2. If nativists assume (ii) they say If nativists assume (ii) they say something something triviallytrivially truetrue..

All knowledge and concepts that one ever All knowledge and concepts that one ever comes to entertain would be innate.comes to entertain would be innate.

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Leibniz’s defense of Leibniz’s defense of nativismnativism

Leibniz claims that there is a Leibniz claims that there is a third possibilitythird possibility that Locke didn’t consider.that Locke didn’t consider.

Ideas as Ideas as dispositions/potentials/inclinationsdispositions/potentials/inclinations/… are /… are something less than actual knowledge. Yet, this something less than actual knowledge. Yet, this amount to assert something more that the mere amount to assert something more that the mere claim that the child has bare potential to claim that the child has bare potential to understand logic etc.understand logic etc.

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The human mind, from birth, has a The human mind, from birth, has a certain certain natural grainnatural grain. .

It is differentially predisposed toward It is differentially predisposed toward employing certain principles and thinking employing certain principles and thinking in some ways rather than others.in some ways rather than others.

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Leibniz opposes Locke’s image of the Leibniz opposes Locke’s image of the tabula tabula rasarasa..

I have also used the analogy of a veined block of marble, I have also used the analogy of a veined block of marble, as opposed to an entirely homogeneous block of marble, as opposed to an entirely homogeneous block of marble, or to a blank table, what the philosophers call a or to a blank table, what the philosophers call a tabula tabula rasarasa. For if the soul were like such a blank tablet, then . For if the soul were like such a blank tablet, then the truths would be in us in the same way as the shape of the truths would be in us in the same way as the shape of Hercules is in a piece of marble when the marble is Hercules is in a piece of marble when the marble is entirely neutral as to whether it assumes this shape or entirely neutral as to whether it assumes this shape or some other. However, some other. However, if there were veins in the block if there were veins in the block which marked out the shape of Hercules rather which marked out the shape of Hercules rather than other shapes, then the block would be more than other shapes, then the block would be more determined to that shape, and Hercules would be determined to that shape, and Hercules would be innate in it, in a way, even though labor would be innate in it, in a way, even though labor would be required to expose the veins,required to expose the veins, and to polish them into and to polish them into clarity, removing everything that prevents their being clarity, removing everything that prevents their being seen. (Leibniz seen. (Leibniz NENE, Preface, 52), Preface, 52)

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The disposition is more than a potential (and The disposition is more than a potential (and less than an actuality).less than an actuality).

Leibniz shares with Descartes the view that Leibniz shares with Descartes the view that dispositions play a central role in the defense dispositions play a central role in the defense of innate ideas.of innate ideas.

We are We are innately programmedinnately programmed to shape the to shape the world in terms of things rather than cluster world in terms of things rather than cluster of features or properties. E.g. it comes more of features or properties. E.g. it comes more natural to us to respond to cats rather than natural to us to respond to cats rather than instances of furriness. (instances of furriness. (vsvs. Quine’s “gavagai” . Quine’s “gavagai” example).example).

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How can dispositions help in unpacking How can dispositions help in unpacking claims regarding mathematical and claims regarding mathematical and logical truths? logical truths?

Leibniz claims that the rules of logic (e.g. Leibniz claims that the rules of logic (e.g. propositional calculus) work within the propositional calculus) work within the grain of the mind.grain of the mind.

How do we explain, then, than most of the How do we explain, then, than most of the time people make fallacies in their time people make fallacies in their reasoning?reasoning?

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Malbranche’s criticismMalbranche’s criticism

The appeal to disposition is explanatory The appeal to disposition is explanatory empty.empty.

It falls under the very same criticism It falls under the very same criticism Descartes addresses to the Scholastic Descartes addresses to the Scholastic notion of dormitive powers. It is a circular notion of dormitive powers. It is a circular explanation.explanation.

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Cf. FragilityCf. Fragility

If: If:

fragility = the disposition to break given fragility = the disposition to break given some circumstances … some circumstances …

then,then,

we explain the glass breaking on the hard we explain the glass breaking on the hard floor by its fragility.floor by its fragility.

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The explanation is merely circular/empty; the The explanation is merely circular/empty; the glass brook when dropped in such glass brook when dropped in such circumstances because it has the property of circumstances because it has the property of breaking in such circumstances.breaking in such circumstances.

The same with a thought.The same with a thought.

If having the idea of a triangle is a disposition If having the idea of a triangle is a disposition to have it in such circumstances/stimulus, then to have it in such circumstances/stimulus, then one has an idea of a triangle when facing such one has an idea of a triangle when facing such circumstances/stimulus.circumstances/stimulus.

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Leibniz’s possible replyLeibniz’s possible reply (he didn’t directly (he didn’t directly address Malbranche’s critique).address Malbranche’s critique).

Both physical and mental dispositions are Both physical and mental dispositions are grounded in non dispositional micro-grounded in non dispositional micro-structural properties of the physical/mental.structural properties of the physical/mental.

In the case of the mind the micro-structure at In the case of the mind the micro-structure at work are the work are the minute perceptionsminute perceptions. They are . They are minute in virtue of their intensive, not minute in virtue of their intensive, not extensive, magnitude. They are too low in extensive, magnitude. They are too low in intensity to become conscious.intensity to become conscious.