Full Idea
We need to distinguish between individual and collective rationality. Collective rationality is what is best for each individual, on the assumption that everyone else will act the same way.
Gist of Idea
Collective rationality is individuals doing their best, assuming others all do the same
Source
Jonathan Wolff (An Introduction to Political Philosophy (Rev) [2006], 1 'Hobbes')
Book Reference
Wolff,Jonathan: 'An Introduction to Political Philosophy (Rev)' [OUP 2006], p.15
A Reaction
Wolff is surmising what lies behind Hobbes's Laws of Nature (which concern collective rationality). The Prisoner's Dilemma is the dramatisation of this distinction. I would making the teaching of the distinction compulsory in schools.
Related Idea
Idea 20498 We should decide whether voting is for self-interests, or for the common good [Wolff,J]