Single Idea 12987

[catalogued under 9. Objects / D. Essence of Objects / 10. Essence as Species]

Full Idea

There are sorts or species such that if an individual has ever been of such a sort or species it cannot (naturally, at least) stop being of it.

Gist of Idea

For some sorts, a member of it is necessarily a member

Source

Gottfried Leibniz (New Essays on Human Understanding [1704], 3.06)

Book Reference

Leibniz,Gottfried: 'New Essays on Human Understanding', ed/tr. Remnant/Bennett [CUP 1996], p.305


A Reaction

Note the thoughtful 'naturally, at least', which blocks genetic engineering. But natural selection is genetic engineering. Crucially, Leibniz is not attributing this to all sorts or species, and allows exceptions.

Related Idea

Idea 12906 Truths about species are eternal or necessary, but individual truths concern what exists [Leibniz]