Functionalism:  The physical implementation of the set of functions which implement a mind are irrelevant to what makes something a mind – it's the functional relations that count.

• Pain occurs when a set of neural fibers is firing. (reductionism)
• Pain is a mental state that occurs as a consequence of physical damage to the system and motivates steps to protect the system from further damage, etc. etc. (functionalism)

Answer 1 is that the mind is a lot like chess, you don’t need to know what the board’s made of you just need to know the rules of the game.

ANSWER 2. The brain is not the right level of abstraction

The brain is made up of billions of neurons each interconnected with maybe a thousand other neurons or so.
The system is too complex to be understood at the hardware level.
Even if you create a perfect neural network simulation that exactly mimics human behavior, you may end up with no idea why it works.
That’s why you need a high level explanation of the mind and behavior, and reductionist explanations just confuse the issue.

ANSWER 3. The brain is none of my business

Acknowledges that understanding the brain is important for understanding the mind.
But also argues that there’s a lot of work to be done just on the software side of things.
Scientists need to specialize, so the work going on in the neurosciences is important, it just isn’t my area of specialization

ANSWER 4. Knowledge of brain function constrains (and allows for tests of ) cognitive theories

The aim of Cognitive Psychology is to provide a high level specification of the information processing steps that the system is using to solve problems
The number of possible theories is huge and alternative theories can often mimic one another.
Any knowledge base that can help to constrain the possible theories is going to be useful to you.
The brain is not a general purpose computer, its likely that structure and function are highly related.
Still the purpose of cognitive psychology is to provide the abstract high level explanation, findings in the neurosciences are just one of many possible constraints on theory.

ANSWER 5. Ultimate goal is reductionism

Yes we want a higher level theory of information processing of the type that cognitive psychology envisions.
Ultimately though we want to associate these information processing steps with particular brain functions.
Denial of functionalism

ANSWER 6. The mind could be in the big toe for all I care!

The mind is largely an illusion, what really exists is the brain.
The constructs studied by Cognitive Psychologists are just relics of our folk psychology.
To really make progress you need to understand the brain qua the brain, you’ll get misled by all of these mentalistic constructs.