Philosophy of Cognitive Science

Lecture 2                                                                                            Dr. Ron Mallon

 

1.  Last time we talked about “what is cognitive science.”  This time, I’d like to start by discussing what is philosophy:

(a) Philosophy is a discipline concerned with the concepts and reasoning exhibited by a discipline.  “Concepts” are the units by which we represent the world to ourselves.  For example, if you think “I like to eat carrots,” the concept carrots is part of your thought, and it represents a thing in the world: carrots.

(b) Some view philosophy as concerned strictly with a priori questions about everyday concepts.  ‘A priori’ means that the questions can be answered without reference to experience; instead, such questions are answered by reflecting upon concepts themselves.  (c) Philosophy of cognitive science is concerned with the conceptual foundations of research into psychology. This includes conceptual disputes that arise in cognitive science concerning empirical research and also to interpret the significance of such research.

 

2.  Modern intellectual thought reveals two broad ways of seeing ourselves.  One way, rooted in our common sense view of our selves as thinking creatures, views us as rational creatures that represent the world to ourselves, reason employing those representations, and choose actions based upon our desires and beliefs.  But modern science allows us to think of ourselves as physical objects: a bag of cells comprised of molecules whose interactions determine our constitution and behavior.  Because modern science has been so successful, it raises deep questions about the first view of ourselves as rational creatures.

The question is: what is the relationship between these two ways of seeing humanity?

 

Cognitive scientists often depict human thought and behavior as existing at multiple ‘levels of explanation’ something like this:

 

M1---------àM2--------àB1              mental level

 

P1--------àP2---------àP3                physical level

 

On the ‘mental level’ we should imagine the terms ‘M1’ and ‘M2’ as being replaced by mental states, and ‘B1’ should be replaced by a behavior.  On the ‘physical level’, we should replace the terms ‘P1’, ‘P2’, ‘P3’ by physical states or states of the human brain, conceived as physical or biological kinds.

 

This suggests that we can think about the question of the two ways of viewing people as a question about how the two ways of describing human thought and behavior are related.  Here are a few options.

 

Eliminativism: The physical level replaces the mental level.

            Eliminativists are impressed by the power of modern scientific explanation, and particularly by brain science.  They think ultimately that psychological explanation of people’s behaviors in terms of things like ‘beliefs’ and ‘desires’ will ultimately fade away.

 

Dualism:  The two levels of explanation are both true descriptions but of two different substances.  Mental terms like ‘belief’, ‘desire’ and ‘pain’ describe states of a distinct, immaterial mental substance.  And the physical descriptions are true of the physical level.

     Problem: Notice that on the ‘mental level’ above, the last state is a behavior.  This is because mental states give rise to behaviors.  And of course, behaviors are physical events.  No one really knows how to make sense of mental states (which are supposed to be states of an immaterial substance) interacting with physical objects in the world.

 

Physicalism:

     Reductive Physicalism:  The mental states are just alternative names for particular states.  For example, perhaps the mental state of being in pain is simply the same as the brain state of ‘C-fiber stimulation’.

Problem:  It seems that we can conceive of a being with mental states but with a very `different physical organization.  For example, it seems we can conceive of a thinking machine, or of a Martian (made of silicone) that enjoys eating ice cream.

     Nonreductive Physicalism:  Mental states are ‘realized’ by physical states, but mental state types are not identical to physical state types.

 

Suppose this last option is correct?  How do we tell what the ‘realization’ relation is?

 

Functionalist Answer: To be in a mental state is to have a state that occupies a certain causal or ‘functional’ role.  For example, let’s say to be angry is to be in a state that has certain characteristic causes (a transgression by another) and certain characteristic effects (hostility and perhaps violence).

 

Functionally characterized states are such that a variety of different physical states can play the same functional role.  For example, consider a shovel, a chair, or a bank president.  In each case, a variety of different objects can count as the thing in question, as long as it performs the function characteristic of the role.

 

In all these cases, we have a role and we have a realizer of the role.

 

3.  Sterelny writes: “One important feature of functionalism is that the theory of the mind is relatively independent of the theory of the brain.”

 

It requires an enormous amount of work to achieve a specification of the function that is characteristic of a mental state.  But specification of this function tells us nothing about the physical realizing state.  And because of the real possibility of multiple realization, the physical stuff may not be all that interesting.