Single Idea 9660

[catalogued under 10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible]

Full Idea

Imaginability is a poor criterion of possibility. We can imagine the impossible provided we do not imagine it in perfect detail and all the time.

Gist of Idea

The impossible can be imagined as long as it is a bit vague


David Lewis (On the Plurality of Worlds [1986], 1.8)

Book Reference

Lewis,David: 'On the Plurality of Worlds' [Blackwell 2001], p.90

A Reaction

In general I agree, but Williamson nicely opposes this view. The fact is that we derive most of our understanding of what is possible from imagination. We just have to realise that we can get it wrong, and so must attend to detail.