Single Idea 5637

[catalogued under 5. Theory of Logic / A. Overview of Logic / 2. History of Logic]

Full Idea

Logicians have come increasingly to realise that logic is the science not of the intension, but of the extension of terms.


'Intension' is the meaning of a word; 'extension' is the things it refers to

Gist of Idea

Nowadays logic is seen as the science of extensions, not intensions


Roger Scruton (Short History of Modern Philosophy [1981], Ch.4)

Book Reference

Scruton,Roger: 'A Short History of Modern Philosophy' [ARK 1985], p.45

A Reaction

I take this to be because the notion of a 'set' is basic, which is defined strictly in terms of its members. This move is probably because we can be clear about extensions, but not intensions. Tidiness is no substitute for complex truth.

Related Idea

Idea 9457 The two main views in philosophy of logic are extensionalism and intensionalism [Jacquette]