3. (Fifth objection): But how could ("seminal) reasons" be different in
the conception of twins, and in the act of generation in the case of
animals who procreate multiple offspring? Here it would seem that when
the individuals are similar, there could be but one single "reason."
No so; for in that case there would not be so many "reasons" as there
are individuals; and, on the contrary, it will have to be granted that
there are as many as there are individuals that differ by specific
differences, and not by a mere lack of form. Nothing therefore hinders
us from admitting that there are different "reasons," even for animal
offspring which show no difference, if there were such. An artist
who produces similar works cannot produce this resemblance without
introducing in it some difference which depends on reasoning; so that
every work he produces differs from the others, because he adds some
difference to the similarity. In nature, where the difference does not
derive from reasoning, but only from differing ("seminal) reasons" the
(individual) difference will have to be added to the specific form,
even though we may not be able to discern it. The ("seminal) reason"
would be different if generation admitted chance as to quantity (the
number of offspring begotten). But if the number of things to be born
is determinate, the quantity will be limited by the evolution and
development of all the "reasons," so that, when the series of all
things will be finished, another period may recommence. The quantity
suitable to the world, and the number of beings who are to exist
therein, are things regulated and contained in the principle which
contains all the "reasons" (that is, the universal Soul), from the very
beginning.