Species

70 Species

The rst [aspect] made for sharp divisions, clear-cut differentiations, among natural

objects, especially among living beings. To range animals and plants in well-dened

species, presumably (since the Platonic dualism of realms of being was still inuential)

corresponding to the distinctness of Eternal Ideas, was the rst business of the student

of the organic world, The other tended to make the whole notion of species appear a

convenient but articial setting-up of divisions having no counterpart in nature. It was,

on the whole, the former tendency that prevailed in early modern biology.^101

In the tension between sharp classication and gradual variation from one form
to another in the Great Chain, we see the early stages of natural species realism,
based on typological denitions, and species nominalism, based on the unreality of
any divisions between them. Much of the early biological debate over species is an
attempt to deal with this tension, and indeed it continues to the present day. This is
made more complicated by the second main developing tradition of the distinction
between “natural” and “articial” classication.

Locke and Leibniz on Real and Nominal Essences

For the natural tendency of the mind being towards knowledge; and nding that, if it

should proceed by and dwell upon only particular things, its progress would be very

slow, and its work endless; therefore, to shorten its way to knowledge, and make each

perception more comprehensive, the rst thing it does, as the foundation of the easier

enlarging its knowledge, either by contemplation of the things themselves that it would

know, or conference with others about them, is to bind them into bundles, and rank

them so into sorts, that what knowledge it gets of any of them it may thereby with

assurance extend to all of that sort; and so advance by larger steps in that which is its

great business, knowledge. This, as I have elsewhere shown, is the reason why we col-

lect things under comprehensive ideas, with names annexed to them, into genera and

species; i.e. into kinds and sorts.

Locke, Essay on human understanding^102

A friend of the Cambridge Platonists and universal language projectors was John
Locke (1632–1704). But Locke was also a friend of Robert Boyle, the atomistic
(“corpuscularean”) chemist, whose philosophy demoted sensory perceptions from
immediate empirical experiences of things to secondary qualities, since we do not
observe the corpuscles of which things are composed. Locke followed Boyle rather
than Bacon in this, and so our knowledge of things must be nominal rather than
essential.^103 Locke is sometimes called a nominalist, and there is a sense in which
this is true, but it relates to his views about names, and not about the underlying
things the names refer to.^104 Names denote abstractions, and some names denote the

(^101) Lovejoy 1936, 227.
(^102) Book II, chap. 32, §6.
(^103) Slaughter 1982, 193–207.
(^104) See Mackie 1976, chapter 3, Fales 1982, who hold that Locke did not deny real essences, but that they
were the underlying substratum, or microstructure; but see also Stanford 1998 for a rejection of the
substratum argument for real essences.