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Single Idea 12987

[filed under theme 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 Ref

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]


The 18 ideas with the same theme [essence for animals is the species they belong to]:

Generalities like man and horse are not substances, but universal composites of account and matter [Aristotle]
Genera are not substances, and do not exist apart from the ingredient species [Aristotle]
'Categories' answers 'what?' with species, genus, differerentia; 'Met.' Z.17 seeks causal essence [Aristotle, by Wedin]
Standardly, Aristotelian essences are taken to be universals of the species [Aristotle, by Witt]
In 'Met.' he says genera can't be substances or qualities, so aren't in the ontology [Aristotle, by Frede,M]
Generic terms like 'man' are not substances, but qualities, relations, modes or some such thing [Aristotle]
In our ideas, the idea of essence is inseparable from the concept of a species [Locke]
If we based species on real essences, the individuals would be as indistinguishable as two circles [Locke]
Internal constitution doesn't decide a species; should a watch contain four wheels or five? [Locke]
For some sorts, a member of it is necessarily a member [Leibniz]
Truths about species are eternal or necessary, but individual truths concern what exists [Leibniz]
Kripke says internal structure fixes species; I say it is genetic affinity and a common descent [Kripke, by Dummett]
Given that Nixon is indeed a human being, that he might not have been does not concern knowledge [Kripke]
Things that gradually change, like species, can still have essences [Devitt]
Essentialism concerns the nature of a group, not its category [Devitt]
It seems that species lack essential properties, so they can't be natural kinds [Dupré]
A species might have its essential genetic mechanism replaced by a new one [Dupré]
Alien 'tigers' can't be tigers if they are not related to our tigers [Almog]