Wednesday, April 26, 2017

Person is not a natural kind

  1. God is not a member of any natural kind.

  2. If person is a natural kind, then every person is a member of a natural kind.

  3. God is a person.

  4. So, person is not a natural kind.


awatkins909 said...

Then substance and essence are not natural kinds either!

Alexander R Pruss said...


awatkins909 said...

Makes me wonder if there is some sort of equivocation fallacy? Some Thomists deny 3 (e.g., Brian Davies) or qualify it, partly because God is substance analogically and person is defined in terms of it.

Also, is this principle true? (Or some better formulated version?): If the (real) definition of Fs is in terms of K1, K2, etc. and some Ki is not a natural kind then neither are Fs. (Just shooting from the hip, haven't thought hard about that principle.)

But then 'man' fails to be a natural kind too (it is defined in terms of substance). Same goes for any other kind of substance. Whereas I'd have taken aristotelian real definitions of substances to give you the natural kinds par excellence, but I guess not? (Note that only substances 'really' have aristotelian real definitions.) Seems a strange result that there could be no natural kinds defined a la Aristotle via genus-et-species in terms of substance.

Christopher Michael said...

(1) is controversial and (3) is only analogously true. This is a better argument:

(1') No angel and I belong to the same natural kind.
(2') If person is a natural kind, then any two persons are members of the same natural kind.
(3') Any angel and I are persons.
(4') So, person is not a natural kind.