Single Idea 18950

[catalogued under 9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta]

Full Idea

Physics is full of references to such 'non-physical' entities as state-vectors, Hamiltonians, Hilbert space etc.

Gist of Idea

Physics is full of non-physical entities, such as space-vectors

Source

Hilary Putnam (Philosophy of Logic [1971], Ch.2)

Book Reference

Putnam,Hilary: 'Philosophy of Logic' [Routledge 1972], p.14


A Reaction

I take these to be concepts which are 'abstracted' from the physical facts, and so they don't strike me as being much of an ontological problem, or an objection to nominalism (which Putnam takes them to be).