If neuroscience makes progress, then the mind is the brain. If the mind is soul-like, then rational thought is inexplicable. If neuroscience does not progress, then the mind is soul- like. If philosophy of mind is vacuous, then the mind is not the brain and rational thought is explicable. So, philosophy of mind is not vacuous.
-Working backward from the conclusion of this argument, which of the following is the most likely justification of the last step of the derivation?
A) Cont
B) MT
C) Taut
D) DS
E) CD

Question

Quizplus · Accepted Answer

The last step of the derivation is "So, philosophy of mind is not vacuous." This is inferred from the contrapositive of the conditional statement "If the mind is not the brain and rational thought is explicable, then philosophy of mind is vacuous." The contrapositive is "If philosophy of mind is not vacuous, then the mind is the brain or rational thought is inexplicable." This statement can be derived using the Modus Tollens (MT) inference rule, which states that if we have a conditional statement "If A, then B" and we know that B is false, then we can infer that A is false as well. Therefore, the correct answer is B.

If Neuroscience Makes Progress, Then the Mind Is the Brain