Species

222 Species

I conjecture that it may be due to the prominence given to Popper by cladists such as
Farris, Wiley, Patterson, Platnick, and Nelson as a justification for cladistic senses of
naturalness.^74 In any event, this is beyond our scope here, the point being that Mayr is
assuming a nominalistic approach to species; the term (as a category) is a useful way
of organizing real, concrete objects (the taxa). He particularly criticizes another phi-
losopher, Philip Kitcher,^75 for failing to appreciate the difference between biological
populations and classes of non-living (inanimate) objects.^76
Of particular note is Mayr’s version of the history of species concepts. He gives
it again in this paper, but he has given various forms of it in his other writings.^77
According to this version,

[t]he biological species concept developed in the second half of the 19th century. Up

to that time, from Plato and Aristotle until Linnaeus and early 19th century authors,

one simply recognized “species,” eide (Plato), or kinds (Mill). Since neither the tax-

onomists nor the philosophers made a strict distinction between inanimate things and

biological species, the species definitions they gave were rather variable and not very

specific. The word ‘species’ conveyed the idea of a class of objects, members of which

shared certain defining properties. Its definition distinguished a species from all oth-

ers. Such a class is constant, it does not change in time, all deviations from the defini-

tion of the class are merely “accidents,” that is, imperfect manifestations of the essence

(eidos). Mill in 1843 introduced the word ‘kind’ for species (and John Venn introduced

‘natural kind’ in 1866) and philosophers have since used the term natural kind occa-

sionally for species... [italics original]^78

In many details this account is incorrect, as the preceding chapters show. A dis-

tinction was made in practice between living and nonliving things by many authors

before the nineteenth century, Locke introduced the term “kind” for species, and

typological accounts permitted variation in the “essential” characters of type to quite

a degree before members of the type became monsters. Mayr seems insistent on

finding “forerunners” to his own preferred conception. He then writes of “the mor-

phological, or typological species concept”:

Even though this was virtually the universal concept of species, there were a number of

prophetic spirits who, in their writings, foreshadowed a different species concept, later

designated [by Mayr, as it happens—JSW] as the biological species concept (BSC).

The first among these was perhaps Buffon (Sloan 1987), but a careful search through

the natural history literature would probably yield quite a few similar statements.

This tendency to seek precursors for a favorite personal view is known among

historians as the “Whig interpretation of history” or as “presentism,” or “creeping

(^74) Hull 1988, 129, 171, 197, 237–239, 247, 251–253, 268, and references cited therein. Nelson and
Platnick’s focus on Popper is due to the work of Walter Bock [Bock 1974, Nelson, pers. comm.],
although Hull [pers. comm.] recalled suggesting Popper to one of them. Popper’s influence on cladis-
tic taxonomy, including the early cladists, is documented in Rieppel 2003.
(^75) K itcher 1989.
(^76) Mayr 1996, 266f.
(^77) Mayr 1957, 1970, 1982, 1991.
(^78) Mayr 1996, 266f.