Species

54 Species

His philosophy inuenced many biologists; especially in this context Bonnet, as
we shall discuss in the next chapter. Later, in the late eighteenth century, at rst
in Buffon, then his pupil Lamarck and Erasmus Darwin in England, but also in
Pierre Maupertuis,^25 Jean-Baptiste Robinet,^26 Denis Diderot,^27 Paul Henri Dietrich
d’Holbach,^28 and Kant, the Great Chain became temporalized. The ladder became
a pathway.
The lex completio and the lex continui, taken together, do not allow for temporal
change as, for example, Leibniz could not allow that there could be more monads
later than earlier.^29 Others, most famously Voltaire, rejected the gradation scale for
the same reason. Things did change, and they weren’t always for the best. One or the
other had to go. As we shall see with Lamarck, the lex completio was the rst of the
two major planks of the Great Chain to be rejected in biology. The Great Chain does
imply that there is no real distinction between species, as all intermediate gaps are
lled. This inuenced Linnaeus in his view of natural classication.^30

Peter Ramus and the Logic of Wholes and Parts

Peter Ramus (1515–1572) was something like a protostructuralist, apparently not

very consistent or even clear in his logical writings.^31 However, he plays a role

here for several reasons. One is that he mediates the anti-Aristotelian views of the

Renaissance humanists like Lorenzo Valla to the post-Reformation age, and in so

doing introduced to intellectual thought both a distinction between articial and

natural logic, but also the tree of Porphyry, which is also occasionally referred to

as the Tree of Ramus (Figure 3.2). A shameless self-promoter, he was censured

by the religious authorities of Catholic France, and was eventually killed in the

St. Bartholomew’s Day Massacre for having converted to Calvinism.

Ramus was greatly dependent upon the terms in which medieval logic was dis-

cussed, but he had an idiosyncratic view of the genus-species distinction. He treated

general terms as based on clusters or groups of simples, and called these genera. He

concluded that species were therefore the same thing as individuals or particulars,

and said that men and women were different species, for which he was condemned

and in which he was followed by various late-sixteenth-century authors. He based

this apparently on the view that words had a single denotation, and that the denota-

tion was of material accidents:

A species is the thing itself concerning which the genus answers [in replying to the

question, What is it?]: thus the genus man answers concerning Plato, the genus dialec-

tician concerning this particular dialectician.^32

(^25) Terrall 2002.
(^26) Robinet 1768, Robinet et al. 1777–1783.
(^27) Diderot 1754.
(^28) Holbach and Mirabaud 1770.
(^29) Lovejoy 1936, 256–258.
(^30) Stevens 1994.
(^31) Ong 1958. Ong’s book is singularly bad tempered, but erudite. The author, a Jesuit and a neo-Thomist,
is attacking the vogue Ramus’ anti-Aristotelian views were having at the time.
(^32) Training in Dialectic, 1543, fol. 14. Quoted in Ong 1958, 204.