Full Idea
The theory that other people besides oneself have mental states is one that has no serious rival.
Gist of Idea
The theory of other minds has no rival
Source
A.J. Ayer (The Central Questions of Philosophy [1973], §VI.E)
Book Reference
Ayer,A.J.: 'The Central Questions of Philosophy' [Penguin 1976], p.134
A Reaction
See 3463, where Searle says there is no such thing as our "theory" about other minds. In a science fiction situation (see 'Blade Runner'), this unrivalled theory could quickly unravel. It could even be a fact that you are the only humanoid with a mind.