Species

Species and the Birth of Modern Science 101

discusses whether all canines are independent creations or descend from a common

stock and are races of the one species. He says in “Determination of the concept of

a human race”

Species and genus [of logic—JSW] are not distinguished in natural history (which has

only to do with ancestry and origin). Only in the description of nature, since it is a mat-

ter of comparing distinguishing marks, does this distinction come into play. What is

species here must there often be called only race.^239

Here Kant identied the different role the terms genus and species play in logic

and natural history. When we are classifying in nature, we make use of the logic in

terms of “identifying marks,” but even so we are only often identifying only subspe-

cic groups (races).

When Did Essentialism Begin?

At this point it might be appropriate to ask when taxic essentialism actually enters
the biological debate, since we have not found it so far. There are several senses in
which we might call some conception of general terms “essentialist.” Locke is an
essentialist about terms, for example, since real essences are hidden from us, but
terms are just names. Kant is an essentialist about mechanisms (such developmental
preformation), particularly of generation, but in line with his phenomena–noumena
distinction suggests that we can only abstract our terms from appearances.
Amundson suggested that essentialism with respect to species did not begin until
the 1840s with the Strickland Code,^240 and for biological species this may be true,
but only in a diagnostic sense. Essentialism, construed as the claim that a general
term or concept must have necessary and sufcient inclusion criteria, or that all
members of a species must share some characters, is a long standing formal notion,
but that when it comes to applying that notion to living things, it was always under-
stood that living species were a different category to formal species.
Let us therefore distinguish, since that is the key to this section, between several
senses of “essentialism.”2 41 We have encountered so far nominal essentialism with
Locke, the view that names can have essences, but only names. Is Strickland’s a
nominal essentialism? Not as Amundson presents it. Strickland is more correctly
understood to be a taxonomic essentialism—that in the process of determining natu-
ral groups, one must nd what actual properties (in this case biological properties)
they have in common. Taxonomic essentialism is a kind of logical essentialism, in
that it relies on the construction of formal, or logical, groups, as Aquinas posed it.
But it is also a material essentialism in Aquinas’ terms, because it relies on mate-
rial properties and not just formal ones. A similar distinction was made by Buridan

(^239) Kant 1785, translated in Greene 1959, 372n from Gesammelte Schriften, VIII, 100n; also translated
in Kant 2007 by Holly Wilson and Günter Zöller.
(^240) Amundson 2005.
2 41 (^) I have given a fuller taxonomy of essentialisms in Wilkins 2013.