mmunicable to all capable of virtue." Further, it is
unreasonable that only the few of any species attain to the end of
the species.

Fifthly, the Philosopher expressly says (Ethic. i, 10), that
happiness is "an operation according to perfect virtue"; and after
enumerating many virtues in the tenth book, he concludes (Ethic. i,
7) that ultimate happiness consisting in the knowledge of the highest
things intelligible is attained through the virtue of wisdom, which
in the sixth chapter he had named as the chief of speculative
sciences. Hence Aristotle clearly places the ultimate felicity of man
in the knowledge of separate substances, obtainable by speculative
science; and not by being united to the active intellect as some
imagined.

Sixthly, as was shown above (Q. 79, A. 4), the active intellect is
not a separate substance; but a faculty of the soul, extending itself
actively to the same objects to which the passive intellect extends
receptively; because, as is stated (De Anima iii, 5), the passive
intellect is "all things potentially," and the active intellect is
"all things in act." Therefore both intellects, according to the
present state of life, extend to material things only, which are made
actually intelligible by the active intellect, and are received in
the passive intellect. Hence in the present state of life we cannot
understand separate immaterial substances in themselves, either by
the passive or by the active intellect.

Reply Obj. 1: Augustine may be taken to mean that the knowledge of
incorporeal things in the mind can be gained by the mind itself. This
is so true that philosophers also say that the knowledge concerning
the soul is a principle for the knowledge of separate substances. For
by knowing itself, it attains to some knowledge of incorporeal
substances, such as is within its compass; not that the knowledge of
itself gives it a perfect and absolute knowledge of them.

Reply Obj. 2: The likeness of nature is not a sufficient cause of
knowledge; otherwise what Empedocles said would be true--that the
soul needs to have the nature of all in order to know all. But
knowledge requires that the likeness of the thing known be in the
knower, as a kind of form thereof. Now our passive intellect, in
the present state of life, is such that it can be informed with
similitudes abstracted from phantasms: and therefore it knows
material things rather than immaterial substances.

Reply Obj. 3: There must ne