### Single Idea 10260

#### [catalogued under 5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence]

Full Idea

Field defines logical consequence by taking the notion of 'logical possibility' as primitive. Hence q is a consequence of P if the conjunction of the items in P with the negation of q is not possible.

Gist of Idea

Logical consequence is defined by the impossibility of P and ¬q

Source

report of Hartry Field (Science without Numbers [1980]) by Stewart Shapiro - Philosophy of Mathematics 7.2

Book Reference

Shapiro,Stewart: 'Philosophy of Mathematics:structure and ontology' [OUP 1997], p.222

A Reaction

The question would then be whether it is plausible to take logical possibility as primitive. Presumably only intuition could support it. But then intuition will equally support natural and metaphysical possibilities.