Full Idea
Putnam implies dispensing with the designation of natural kinds by singular terms in favour of the postulation of necessary but a posteriori connections between predicates. ...We might call this 'predicate essentialism', but not 'de re essentialism'.
Gist of Idea
Express natural kinds as a posteriori predicate connections, not as singular terms
Source
report of Hilary Putnam (Explanation and Reference [1973]) by Penelope Mackie - How Things Might Have Been 10.1
Book Reference
Mackie,Penelope: 'How Things Might Have Been' [OUP 2006], p.169
A Reaction
It is characteristic of modern discussion that the logical form of natural kind statements is held to be crucial, rather than an account of nature in any old ways that do the job. So do I prefer singular terms, or predicate-connections. Hm.