more from this thinker | more from this text
Full Idea
My knowing that I had a hidden birth-mark would not entitle me to infer with any great degree of confidence that the same was true of everybody else.
Gist of Idea
You can't infer that because you have a hidden birth-mark, everybody else does
Source
A.J. Ayer (The Central Questions of Philosophy [1973], §VI.E)
Book Ref
Ayer,A.J.: 'The Central Questions of Philosophy' [Penguin 1976], p.134
A Reaction
This is the notorious 'induction from a single case' which was used by Mill to prove that other minds exist. It is a very nice illustration of the weakness of arguments from analogy. Probably analogy on its own is useless, but is a key part of induction.
| 15770 | Some things cannot be defined, and only an analogy can be given [Aristotle] |
| 4636 | All reasoning concerning matters of fact is based on analogy (with similar results of similar causes) [Hume] |
| 6961 | An analogy begins to break down as soon as the two cases differ [Hume] |
| 5555 | Philosophical examples rarely fit rules properly, and lead to inflexibility [Kant] |
| 5331 | You can't infer that because you have a hidden birth-mark, everybody else does [Ayer] |
| 6574 | Legal reasoning is analogical, not deductive [Fogelin] |
| 7465 | Babylonian thinking used analogy, rather than deduction or induction [Watson] |
| 16307 | Don't trust analogies; they are no more than a guideline [Halbach] |