Single Idea 11909

[catalogued under 9. Objects / D. Essence of Objects / 5. Essence as Kind]

Full Idea

There is a disanalogy between 'necessarily water=H2O' and 'necessarily Hesperus=Phosphorus'. The second just needs the necessity of identity, but the first needs 'x is a water sample' and 'x is an H2O' sample to coincide in all possible worlds.

Gist of Idea

Unlike Hesperus=Phosophorus, water=H2O needs further premisses before it is necessary

Source

Penelope Mackie (How Things Might Have Been [2006], 10.1.)

Book Reference

Mackie,Penelope: 'How Things Might Have Been' [OUP 2006], p.198


A Reaction

This comment is mainly aimed at Kripke, who bases his essentialism on identities, rather than at Putnam.