Full Idea
The argument from analogy is a weak one, because it does not logically guarantee the inference I draw to the other's inner states, for he might be dissimulating or acting, or may even be a cleverly contrived robot which feels nothing.
Gist of Idea
The argument from analogy is not a strong inference, since the other being might be an actor or a robot
Source
A.C. Grayling (Wittgenstein [1988], Ch.3)
Book Reference
Grayling,A.C.: 'Wittgenstein' [OUP 2001], p.100
A Reaction
This gives the impression that for an argument to be strong it must logically guarantee its inference. It strikes me that analogy is a good reason for believing in other minds, but that is because I am looking for the best explanation, not logical proof.