Causal Theoretical Functionalism Lecture 2.4

Causal theoretical functionalism is a position held by those who support the general idea of functionalism and non-reductive physicalism.
The core intuition is that the mind is what the mind does. The nature of a thought is defined by the causal role that thought plays within the system.
It supports the idea of multiple realizability, meaning mental states can be realized by various physical states, and as such, it rejects the identity theory.
A specific motivation for this branch of functionalism is the critique of computational functionalism. While computational functionalism reduces psychology to information processing and computing, critics argue this may capture cognition but fails to account for the full picture of psychology, specifically including sensation and perception.
Causal theoretical functionalism seeks a more generic account of the mental based on whatever set of causal powers and causal roles mentality possesses that lead us to speak and think about it.

This method is named after Frank Ramsey (pictured at the top in the lecture) and David Lewis (pictured at the bottom; Lewis applied and popularized the method much later than the original work by Ramsey).
The method involves transforming psychological theories into formal logical expressions to define mental states by their relations to one another and to inputs and outputs.

Collect the Theory: Gather all statements belonging to a specific theory of psychology.
- Example: A segment of cat-related psychology: "Seeing cats leads to a belief in cats, which combined with a desire for companionship leads someone to adopt a cat."
Replace Predicates with Variables: Every psychological predicate (e.g., seeing, belief, desire) is replaced with a variable ( $m_1$ , $m_2$ , $m_3$ , etc.).
Apply Existential Quantifiers: Place an existential quantifier ( $\exists$ ) at the front of the sentence for each variable. This effectively says "there exists a state $m$ such that…"

The statement is transformed to: $\exists m_1 \land \exists m_2 \land \exists m_3$ such that if $x$ (some person) is in state $m_1$ towards cats, then $x$ will be in state $m_2$ regarding cats, and if $x$ is in state $m_2$ and state $m_3$ , then $x$ will adopt a cat.
In this scenario:
- $m_1 =$ The state of "seeing"
- $m_2 =$ The state of "believing"
- $m_3 =$ The state of "desiring companionship"

The method provides a way to reduce psychology to causal theoretical functions by deleting specific psychological terms and observing what remains to fill the blank.
Learning Meaning through Use: The method mirrors how humans actually learn language. Meaning is rarely learned through dictionary definitions; rather, it is acquired by hearing words used in a variety of contexts until the user understands that the word refers to the "fill in the blank" that fits all those observed contexts.
Holistic View: If we take a comprehensive, holistic view of language and delete one word, the remaining network of relationships provides the meaning of that word.

A central question in causal theoretical functionalism is: Which psychology should be subjected to the Ramsey-Lewis method?

Common Sense Psychology: David Lewis assumed the use of ordinary, every-day language (e.g., terms like belief, desire, perceive, consider, intelligence).
Scientific Psychology: Critics argue we should use the theories of trained psychologists, as scientific psychology might provide a significantly different and more accurate account of the mind than common sense.

Truth of the Theory: To produce a physicalistic theory, the chosen psychological theory must be true and fulfilled by the world. If the theory is false, the ramification model fails.
Disagreement on Concepts: If two people disagree on the psychological concepts being ramified, the Lewisian view might suggest they are simply using different concepts rather than engaging in a real dispute. This raises questions about how genuine disagreements about mental concepts can occur.

Functionalist theories are frequently criticized for ignoring qualitative conscious states (qualia).

This concern suggests that two people can be in functionally equivalent states that are qualitatively different in their phenomenal experience.
The Color Invert Scenario:
- Suppose Person A and Person B live in our world. What green looks like to Person A is what red looks like to Person B.
- Functionally and behaviorally, they are identical. When seeing a green parrot, both might say the word "green," form the same beliefs, and have the same reactions.
- Because they are functionally indistinguishable, functionalism cannot account for the fact that their internal conscious experiences are actually different (red vs. green).

This example involves a hypothetical mad neurosurgeon who cross-wires a subject's brain.
The Procedure:
- Inputs intended for "sweet" receptors are redirected to "sour" receptors.
- Inputs intended for "itch" receptors are redirected to "pain" receptors.
The Result:
- When the person is pinched, they experience an itch. When they touch poison ivy, they experience pain.
- However, their functional reactions remain aversive (they still recoil from pain/ivy). They might call their pains "itches" and their sour tastes "sweet," puckering their lips at the "sweet" taste.
Conclusion: If this scenario is conceivable, it demonstrates that functional similarities miss the qualitative experience (qualia), which is a significant part of the "big picture" of the human mind.