Species

The Medieval Bridge 43

nearly all can be identied with a modern species.^54 Nevertheless, Albert did list in
Book VII 54–64, ve ways plant species could change their species: by improvement
or deterioration of seed, by being cut down and shoots being of another species,
when cuttings grow as vines rather than oaks (“in Alvernia”), when a tree grows
rotten and springs forth a different plant, and by grafting. Amundson considers this
a kind of species mutability,^55 but I suspect it is due more to the fact that in cultiva-
tion, “species” is not the same thing as a biological species, but rather a synonym for
“kind.” As Stannard notes

In medieval nomenclature, genus, species, varietas, and forma were used interchange-

ably. Sometimes Albert uses genus to denote what we would accept as a genus ... but

in other places his genus is practicably equivalent to our species ...^56

The persistence of the pre-scientic tradition of the herbals, and of spontaneous

generation, has something to do with the fact that as a heretic, Frederick’s work was

not a safe source for later workers—indeed later writers accused him of atheism

and heresy on several counts. But since Albert’s work was used, and indeed he was

canonized, it becomes hard to account for this purely in those terms. Rather, it seems

that what stopped Frederick, Albert, and others such as Roger Bacon from inuenc-

ing natural history and inaugurating an early empiricism was the fact that natural

history was not seen as an end in itself until much later, but rather as an adjunct to

theology and homiletics. That said, it is worth noting that a scientic attitude was

not beyond the reach of a medieval educated man like Frederick, and that acuity of

observation, when driven by immediate interests for which accurate information was

required, was something that could be attained in a way that is quite modern. The

shift to factual science can thus be seen to be driven by practical matters—in this

case, falconry. However, there was a decline in empirical work on animals and plants

in the fourteenth century and for a century after.^57

ST. THOMAS: [LOGICAL] SPECIES AS INDIVIDUALS

Thomas Aquinas’ (1225–1274) discussion in the Summa (Book I, Q. 86)^58 does not

materially advance the matter and can be treated for our purposes here as straight

transmission of the prior Scholastic logic. Aquinas treats it as a question of knowl-

edge, and the “species” he considers is that of species intelligibilus (a n swer 1):

Our intellect cannot know the singular in material things directly and primarily. The

reason of this is that the principle of singularity in material things is individual matter,

whereas our intellect, as I have said above, understands by abstracting the intelligible

species from such matter. Now what is abstracted from individual matter is the univer-

sal. Hence our intellect knows directly the universal only.

(^54) Stannard 1979.
(^55) Amundson 2005, 36.
(^56) Stannard 1980, 366n.
(^57) Most likely due to the Black Death. A similar issue arises with medieval logic.
(^58) Aquinas 1947.