3

1

The Classical Era:

Science by Division

The history of the species concept can be divided into a pre-biological and a post-
biological history, which is how the Received View has always treated it. But the two
histories overlap substantially, and it is much better to consider instead the history of
the species idea that applies to any objects of classication—the tradition of univer-
sal categorization and philosophical logic—and, independently, the particular his-
tory of the species idea that applies solely to biological organisms. Even though, for
example, Linnaeus in his third volume of his Systema Naturae^1 famously applied the
notion species to minerals as well as organisms, his biological usage included ele-
ments not included in the mineralogical case. We must therefore separate universal
(logical or formal) categorical and biological taxonomic notions of species.^2
We can thus distinguish between two broad kinds of taxonomy. Universal cate-
gories are what the philosophical tradition from Plato to Locke sought (but which
continues through to the considerations of sensory impressions, or qualia, by the
logical positivist and phenomenological philosophical schools) and in which spe-
cies are any distinguishable or naturally distinguished categories with an essence or
denition. Then there is the biological taxonomy that develops from this tradition
as biology itself develops from the broader eld known as “natural history.”^3 These
biological notions of species do not necessarily refer to reproductive communities,
nor do they in the medical denitions of species of diseases of the period,^4 but we
do need to recognize that “species” develops a uniquely biological avor around the
seventeenth century.^5
These two conceptions form what might be regarded as part of or an entire
research program, in Lakatos’ sense. The universal taxonomy program that began
with Plato culminates in the attempt to develop a classication of not only all natural
objects, but all possible objects. It continues in the modern projects of metaphysics

(^1) Linné 1788−1793 Vol. 3.
(^2) This account owes its outline and many details to Nelson and Platnick 1981, and Panchen 1992.
(^3) “History” is, in this older sense, the Greek word historia, which means an inquiry or investigation,
which derives from the title, or rather the opening words, of Herodotus’ History. Later it comes to
mean “knowledge” or “learning.”
(^4) Cain 1999. The classication of diseases is called nosology, and it wrestles with many of the same
issues that systematics does, especially in psychiatry. See Murphy 2006, Regier et al. 2009, Kendler
and Parnas 2015.
(^5) An excellent treatment of many of the themes discussed in this section, and a good aid to understanding
the historical contexts, can be found in Mary Slaughter’s wonderful book [Slaughter 1982]; a broader
and more liberal treatment, but one that suffers from over-theorizing, is Michel Foucault’s The Order
of Things (Les Mots et les Choses) [Foucault 1970], particularly chapter 5. Much of the source material
and a detailed discussion of the logica combinatorialis can be found in Rossi’s treatment [Rossi 2000]
relating mnemotechnical (ars memoria) traditions and the Universal Language Project.