Thirdly we have the limiting cases of this in the inductive syllogism 5ui 7riu'mw, 7 a syllogism in the third figure concluding universally, and yet valid because the copula expresses equivalence, and in analogy 8 in which, it has been well said, instances are weighed and not counted.
One of these, Summa de assumpto homine, is of a theological character, dealing with the humanity of Christ; the other, Summa de matrimonio, is a legal argument, to the effect that the essential fact in marriage is neither, as Gratian maintains, the copula, nor, as Peter Lombard, consent by verba de praesenti, but mutual traditio.
Moreover, it is very probable that conjugation occurs soon after the arrival of the parasites in their specific invertebrate host; and this act may perhaps give rise to an aflagellar copula, which is gregariniform and comparable to an ookinete.
Afterwards (chap. so) proceeding to the opposition of propositions, he adds the form called tertii adjacentis, in a passage which is the first appearance, or rather adumbration, of the verb of being as a copula.
The words introducing this form (6Tav bE TO '&TL Tptrov irpoo-KaTnyopijTac, chap. so, s 9 b s 9), which are the origin of the phrase tertii adjacentis, disengage the verb of being (g un) partially but not entirely, because they still treat it as an extra part of the predicate, and not as a distinct copula.