Species

34 Species

UNIVERSALS VERSUS NOMINALISM: SPECIES

ARE IN THE UNDERSTANDING

There was little advancement on biological species concepts in the medieval period,

which is usually delimited from 500 to 1500 . This is not because the medievals

were unimportant—very far from it. The revival of the universals debate in the late

eleventh century by Roscelin (of Compiègne, c. 1050–c. 1125), and Peter Abelard

(1079–1142) was critical in bringing the notion of genera and species to the forefront

of western thinking.^4 Once there, the idea was taken up by the nascent biological sci-

ences in the seventeenth century, but so far as I can tell, nominalism did not directly

inuence biological practice, although it did inuence John Locke in the seventeenth

century in ways that then affected natural historians. To understand the signicance

of this, we must understand the philosophical arguments.

Universals were terms or classes that covered many individual objects (“indi-

viduals”) but which remained one; in other words, a universal was something that

existed across many things. How it did that was the subject of a long debate from

Porphyry onward. As we have seen, Porphyry and Boëthius presented the problem—

whether universals exist in the mind or in reality—but did not resolve it. Over the

next few centuries, three positions were set up:

1. Realists
   a. Moderate Realists
   b. Strong Realists (sometimes called “Extreme” or “Robust” Realists^5 )


2. Nominalists^6

Realists held that what united all the individuals under a universal term existed in

reality. In other words, a universal was a feature of the world. Moderate Realists held

that universals existed in the individual objects; roughly the straight Aristotelian

metaphysical position. Strong Realists held that universals could exist (and did) even

if nothing existed that fell underneath them. For example, a Moderate Realist might

say that Goodness existed in every good person, but if there were no good people

(excluding God for the purposes of argument) there was no Goodness in the world. A

Strong Realist would say that Goodness existed whether or not there were any good

beings. This is pretty well Plato’s view (under the heading The One and the Many).

This split basically set the options open until the fourteenth century, when nominal-

ism was formulated.

Nominalists, in the early fourteenth century, held that universals are just concepts

in the mind (or in words, which went by the phrase flatus vocis or “breath of the

voice”; i.e., a mere sound), and that all that is real are the named individual objects—

this man, that horse, that rock. Consequently, nominalists denied the existence out-

side the mind of logical categories. Realists rejected this and held that knowledge

(scientia) required the existence of universals outside the mind.^7 The nominalists

(^4) Leff 1958. An excellent overview of the universals debate is given by Aaron 1952.
(^5) Brower 2016, 733.
(^6) Dutton 2006.
(^7) Brown 1999.