The Argument from Reason (again)

You are now in a position to understand a more formal presentation of the argument from reason. This version will also be presented a bit too quickly, but you should be able to grasp its point.

Consider the following argument:

All humans are mortal
Socrates is a human
Hence, Socrates is mortal.

The argument is valid: the truth of the premises guarantees the truth of the conclusion. If the premises are the true the conclusion must be true. It is not possible for the premises to be true and the conclusion false. The point with all of these different ways of saying the same thing is that there is a logical connection between the premises of the argument and its conclusion. We can grasp that connection via reason.

Now suppose that materialism is true. If materialism is true, then humans are wholly material beings--there are no non-material features of humans (no immaterial minds, souls, spirits, etc). Materialism is the dominant view of most scientists, especially biologists, cognitive scientists, neuroscientists, psychologists, etc. If humans are wholly material beings, then mental states (states like believing, desiring, loving, hoping, wishing, fearing, etc) are material states. Hence, if materialism is true then mental states are material states. If mental states are material states, then the possible relations between mental states cannot be different from the possible relations between material states. So, the argument we considered above had better exhibit relations that can be had by material states. Does it?

If mental states are material states, then if there are logical connections between mental states, there must be logical connections between material states. But there are not logical connections between material states. Hence, either there are no logical connections between mental states or mental states are not material states. But there are logical connections between material states (see the above argument about Socrates). So, mental states are not material states. Hence, humans are not wholly material beings. Hence, materialism is false. To see why material states do not relate to each other logically, consider this:

If all humans are mortal and Soc is a human, then Soc must be mortal. If materialism is true, then each of the three mental states just referred to (the states of thinking 'All humans are mortal', 'Soc is a human', and 'Soc must be mortal') are material states, namely, brain states (or neuronal states). So, let's assign each mental states to a brain state:

All humans are mortal = Brain state 1
Soc is a human = BS 2
Soc must be mortal = BS 3

So, we now have the following:
If BS1 and BS2, then it must be the case that BS3.

But, that's false. A brain can be in BS1 and BS2 and fail to be in BS3 for all sorts of reasons. The main reason is that movement from brain states to other brains states is a matter of causation. The relation between brain states is a causal relation not a logical one. Hence, the relation between mental states or thoughts is not the same as the relation between brain states. Hence mental states are not brain states. THE END.

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