The argument from Analogy

Q - Why do you think that the argument from analogy doesn’t work? In particular why is it a bad inductive argument?

The argument from analogy is used to justify our belief in the existence of other minds apart from our own.

The argument from analogy runs as follows: I infer from the fact that certain mental states of my mind accompany physical states of my body that my mind and body are 'connected' i.e. there is a "symbiotic" link between my mental states and my bodily behaviour. I can observe other bodies behaving in a similar fashion to my own, I therefore infer that those other bodies have minds which are similarly connected with those bodies.

The argument is inductive by nature, it infers the existence of other minds from the similarity of bodily behaviour. From the specific case of my own nature I make a generalisation about other people's nature.

There are a number of potential weaknesses with the argument from analogy:
1. Challenges based on dualism - how we know that my mind and body are both distinct but "mine". We cannot experience anything other than mental states - physical entities cannot be experienced directly, only indirectly (the indirect realism argument). Therefore, if we cannot be sure of the existence of our own bodies, we cannot infer the existence of other people's minds from the un-knowable relationship between my own mind and body.
2. Challenges based on the supposed weakness of the form of inductive arguments (as discussed in the previous module). Why should we suppose that other people are the same as we are?
3. Radical scepticism about the existence of an external world. We cannot prove that an external world exists at all, therefore we cannot prove that other people exist at all. The Brain In Vat argument is an example of this form of challenge. This argument is similar in nature to 1.