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EMERGENCE in PHILOSOPHY of MIND Achim Stephan, Institute of Cognitive Science University of Osnabrück
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EMERGENCE in PHILOSOPHY of MIND

Achim Stephan, Institute of Cognitive ScienceUniversity of Osnabrück

2

Candidates for “emergence”

• Novelty

• Unexpectedness

• Unpredictability

• Irreducibility

• Unintended or unprogrammed arising

• Capacities not explicitly programmed

3

The Heyday of Emergentism

What has generally been perceived as the ‘heyday of emergentism’ comprises mainly the first half of the 1920s.

In quick succession, these years saw the publication of the main works of British and American Emergentism:

4

Samuel Alexander (1859-1938)

Gifford Lectures 1916-18

• Space, Time, and Deity. Two Volumes. London: Macmillan, 1920.

5

Conwy Lloyd Morgan (1852-1936)

Gifford Lectures 1922

• Emergent Evolution. London: William & Norgate, 1923.

• Life, Mind, and Spirit .London: William & Norgate, 1926.

6

C.D. Broad (1887-1971)

Tarner Lectures 1923

• The Mind and its Place in Nature. London: Routledge, 1925

• http://www.ditext.com/broad/mpn/mpn.html

7

Roy Wood Sellars (1880-1971)

• Evolutionary Naturalism. La Salle: Open Court, 1922.

• The Principles and Problems of Philosophy.New York: MacMillan, 1926.

8

The Fate of Emergentism?

... the Emergentists left the dry land of the a priori to brave the sea of empirical fortune. They set off in a certain direction, and for awhile winds of evidence were in their sails; but the winds gradually diminished, and eventually ceased altogether to blow their way. Without these winds in its sails, the British Emergentist movement has come to an almost complete halt. (Brian McLaughlin)

9

Relativistic Emergentism

“The occurrence of a characteristic W in an object w is emergent relative to a theory T, a part relation Pt, and a class G of attributes if that occurrence cannot be deduced by means of T from a characterization of the Pt-Parts of w with respect to all the attributes in G. [...] A characteristic W is emergent relatively to T, Pt, and G if its occurrence in any object is emergent in the sense just indicated.” (Hempel & Oppenheim 1948; 1965, 263)

10

The Revival of Emergentism

In the heyday of positivism and reductionism, emergentism used to be ridiculed as an example of unsavory pseudo-scientific doctrines, not quite as disreputable as, say neo-vitalism, with its entelechies or elan vital, but almost as mysterious and incoherent. With the decline of positivism and the demise of ‘unified science’, however, emergentism has been showing strong signs of revival ... (Jaegwon Kim)

11

The need for strong emergence in the philosophy of mind

• Can mental properties such as the having of intentional or phenomenal states be reductively explained by reference to some physical/neuronal base?

Synchronic emergentism

12

Varieties of Emergentism

Three theories among the different varieties of emergentism deserve particular attention:

• (strong) synchronic emergentism,

• diachronic (structure) emergentism, and

• weak emergentism.

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Varieties of emergentism

Synchronic emergentism

Weak emergentism

Diachronic emergentism

14

Varieties of Emergentism

Weak emergentism specifies the minimal criteria for emergent properties. Its three basic features

– the thesis of physical monism,

– the thesis of systemic (or collective) properties, and

– the thesis of synchronic determination

are perfectly compatible with current reductionist approaches.

15

Varieties of Emergentism

The more ambitious theories of emergence have their common base in weak emergentism, and can be developed by adding further theses.

Diachronic emergentism acknowledges such aspects as novelty and unpredictability.

Synchronic emergentism refers to the feature of irreducibility.

16

Weak Emergentism

The first thesis of current theories of emergence concerns the nature of systems that have emergent properties.

According to it, all possible candidates for emergent properties such as, e.g., being alive, hearing a D-minor accord, or feeling anger, are instantiated only by material systems with a sufficiently complex microstructure.

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Physical monism

• Entities existing or coming into being in the universe consist solely of physical constituents.

• Properties, dispositions, behaviors, or structures classified as emergent are instantiated by systems consisting exclusively of physical entities.

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Weak Emergentism

The thesis of physical monism denies that there are any supernatural components such as an entelechy or a res cogitans responsible for a system’s having emergent properties.

Particularly, this means that living or cognizing systems – whether artificial or natural – consist of the same basic parts as lifeless objects of nature.

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Weak Emergentism

While the first thesis places emergent properties and structures within the framework of a physicalistic naturalism, the second thesis – the thesis of systemic properties – delimits the type of properties that are possible candidates for emergents.

It is based on the idea that the general properties of a complex system fall onto two classes:

those that some of the system’s parts also have, and those that none of the system’s parts has.

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Weak Emergentism

Examples of the first class are properties such as being extended and having a velocity.

Examples of properties of the second class are flying, reproducing, breathing, or having a sensation of an itch.

These properties are called systemic or collective properties.

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Systemic properties

• Emergent properties are systemic (or collective) properties.

• A property of a system is systemic if and only if the system possesses it but no part of the system possesses it.

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Weak Emergentism

While the first thesis restricts the type of parts out of which systems having emergent properties may be built, and

while the second thesis characterizes in more detail the type of properties that might be emergent,

the third thesis specifies the type of relationship that holds between a system’s microstructure and its emergent properties as a relationship of synchronic determination:

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Synchronic Determination

• A system’s properties and its dispositions (to behave in a certain way) depend nomologically on its microstructure.

• There can be no difference in a system’s systemic properties without some difference in the properties of its parts or in the arrangement of its parts.

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Weak Emergentism

Anyone who denies the thesis of synchronic determination has either to admit properties of a system that are not bound to the properties and arrangement of its parts, or to suppose that some other factors, in this case non-natural factors, are responsible for the different dispositions of systems that are identical in their microstructure.

Both seem implausible.

25

Problems of weak emergentism

• Weak emergentism does cut nature at one of its joints.

• Nevertheless it is not very interesting to classify some specific property as weakly emergent.

• There exist just too many weakly emergent properties.

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Weak Diachronic Emergentism

Weak emergentism+ Novelty

In the context of both evolutionary processes and the development of new artifacts, adding the thesis of novelty can enrich weak emergentism.

It makes available a diachronic perspective.

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Novelty

• In the course of evolution exemplifications of genuine novelties occur again and again.

• Existing building blocks develop new configurations; new structures are formed that constitute new entities with new properties and behaviors.

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Weak Diachronic Emergentism

The thesis of novelty does not by itself turn a weak theory of emergence into a strong one, since reductive physicalism remains compatible with such a variant of emergentism, which we might call weak diachronic emergentism.

Only the addition of the thesis of unpredictability, in principle, will lead to stronger forms of diachronic emergentism that might be relevant for cognitive science.

29

The need for strong emergence in the philosophy of mind

• Can mental properties such as the having of intentional or phenomenal states be reductively explained by reference to some physical/neuronal base?

Synchronic emergentism

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Synchronic Emergentism

Weak emergentism+ Irreducibility

A systemic property is irreducible (and thus synchronically emergent) if it cannot be explained reductively.

31

Synopsis

Synchronic emergentism

Weak emergentism

Weak diachronic emergentism

+ novelty

+ irreducibility

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Reductive Explanation

A reductive explanation is successful if the following conditions are met

– The property to be reduced must be functionally construable or reconstruable

– It must be shown that the specified role is filled by the system’s parts and their mutual interactions

– The behavior of the system’s parts must follow from the behavior they show in isolation or in simpler systems than the system in question

33

Kim’s Priming procedure

“To reduce a property M to a domain of base properties we must first ‘prime’ M for reduction by construing, or reconstruing, it relationally or extrinsically.

This turns M into a relational/extrinsic property.”

(Kim 1998, p. 98).

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Levine’s two stages

“Stage 1 involves the (relatively? quasi?) a priori process of working the concept of the property to be reduced ‘into shape’ for reduction by identifying the causal role for which we are seeking the underlying mechanisms.

Stage 2 involves the empirical work of discovering just what those underlying mechanisms are.”

(Levine 1993, p. 132).

35

Reduction Task 1

Given that system S has macro-property P. Provide a reductive explanation for P!

(Refer to the microstructure MS(S), the simple laws and the interaction laws that hold true for the components Ci of S and show that S must have P. Make use of adequate conceptual preparations.)

36

Reduction Task 2

Given a system S with microstructure MS(S).

Discuss whether or not S has macro-property P! If so, show this by a reductive explanation!

(Refer to the microstructure MS(S), the simple laws and the interaction laws that hold true for the components Ci of S and show that S must have P. Make use of adequate conceptual preparations.)

37

Synchronic emergentism

• A systemic property is irreducible if (either)– It is not functionally construable or reconstruable– It cannot be shown that the interactions between

the system’s parts fill the systemic property’s construed (or reconstrued) functional role

– The behavior of the system’s components, over which the systemic property supervenes, does not follow from the component’s behavior in isolation or in simpler configurations

38

Synchronic emergentism

In present-day terminology, the thesis of irreducibility specifies exactly the same conditions for synchronic emergence as implicitly contained in Broad’s distinction between mechanistic and emergent theories.

In a “classical” passage in his book The Mind and its Place in Nature, Broad says:

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Put in abstract terms the emergent theory asserts • that there are certain wholes, composed (say) of

constituents A, B, and C in a relation R to each other; • that all wholes composed of constituents of the same kind

as A, B, and C in relations of the same kind as R have certain characteristic properties;

• that A, B, and C are capable of occurring in other kinds of complex where the relation is not the same kind as R; and

• that the characteristic properties of the whole R(A,B,C) cannot, even in theory, be deduced from the most complete knowledge of the properties of A, B, and C in isolation or in other wholes which are not of the form R(A,B,C).

The mechanistic theory rejects the last clause of this assertion (1925, 61).

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Put in abstract terms the emergent theory asserts that there are certain wholes, composed (say) of

constituents A, B, and C in a relation R to each other;

R(A,B,C)A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal conditionR(A,B,C)

A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal condition

41

that all wholes composed of constituents of the same kind as A, B, and C in relations of the same kind as R have certain characteristic properties;

R(A,B,C)A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal conditionR(A,B,C)

A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal condition

42

that A, B, and C are capable of occurring in other kinds of complex where the relation is not the same kind as R; and

R(A,B,C)A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal conditionR(A,B,C)

A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal condition

43

that the characteristic properties of the whole R(A,B,C) cannot, even in theory, be deduced from the most complete knowledge of the properties of A, B, and C in isolation or in other wholes which are not of the form R(A,B,C). (Broad, 1925)

R(A,B,C)A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal conditionR(A,B,C)

A,B,CS1(A,B), S2(A,C), S3(B,C)R1(A,B,D), T1(A,C,D,F)

PRve

rtic

al c

ondi

t ion

horizontal condition

44

Emergence in the philosophy of mind

If you are interested in reductively explaining mental phenomena then you better provide all you can get as a possible reduction base, e.g.,

– the complete physical system– its parts– their arrangement and interactions, plus – relevant features of the environment …

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The Problem of Phenomenal Qualities

(1) The problem of phenomenal qualities is the problem of whether or not phenomenal qualities can be reductively explained.

(2) Reductive explanations of phenomenal qualities afford conceptual reconstruction via their causal role.

(3) Phenomenal qualities resist their preparation for reduction (there are no reconstructions via their causal role).

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Reasons for Resistance

“What seems to be responsible for the explanatory gap, then, is the fact that our concepts of qualitative character do not represent, at least in terms of their psychological contents, causal roles. … Thus, to the extent that there is an element in our concept of qualitative character that is not captured by features of its causal role, to that extent it will escape the explanatory net of a physicalistic reduction.” (Levine 1993, 134).

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Broad’s early resistance

“If the emergent theory of chemical compounds be true, a mathematical archangel, gifted with the further power of perceiving the microscopic structure of atoms as easily as we can perceive hay-stacks, could no more predict the behaviour of silver or of chlorine or the properties of silver-chloride without having observed samples of those substances than we can at present.

Would there be any theoretical limit to the deduction of the properties of chemical elements and compounds if a mechanistic theory of chemistry were true? Yes.” (Broad 1925, 71)

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Broad’s early resistance

“Take any ordinary statement, such as we find in chemistry books; e.g.,

‘Nitrogen and Hydrogen combine when an electric discharge is passed through a mixture of the two. The resulting compound contains three atoms of Hydrogen to one of Nitrogen; it is a gas readily soluble in water, and possessed of a pungent and characteristic smell.’

If the mechanistic theory be true the archangel could deduce from his knowledge of the microscopic structure of atoms all these facts but the last.” (ib.)

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Broad’s early resistance

“The utmost that he could predict on this subject would be that certain changes would take place in the mucous membrane, the olfactory nerves and so on.

But he could not possibly know that these changes would be accompanied by the appearance of a smell in general or the peculiar smell of ammonia in particular, unless someone told him so or he had smelled it for himself.” (ib.)


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