Chisholm v. Classical Compatibilism: Part I

The classical compatibilist argues that properly understood, the thought that we're accountable for having done something only if we could have done otherwise does not yield the conclusion that if determinism is true, we're accountable for nothing.

According to the classical compatibilist, what we indicate by utterances of "x couldn't have done otherwise" is that x lacked the ability to do otherwise. This, in turn, gets understood as its being false that if x had decided to do otherwise, then would have done otherwise.

Thus, on the classical compatibilist view,

x is accountable for y only if x could have done otherwise [call this PAP]

should be understood as

x is accountable for y only if it is true that had x decided otherwise, x would have done otherwise. [call this PAPC]

As it happens, on this construal, the idea that accountability requires the ability to do otherwise is no barrier to accepting that we're both determined and accountable.

Sadly, as Chisholm argues, it is far from clear that PAP is equivalent to PAPC. The problem is this: it could be true that you would have done otherwise, had you decided to, but false that you could have done otherwise.

His argument goes like this:

(1) Suppose that you couldn't have decided to do anything other than what you did decide to do.

(2) Therefore, you could not have done anything other than what you did do.

(3) But, it might nonetheless be true that you would have done something else had you decided to do something else.

(4) Therefore, PAP is not equivalent to PAPC.