“Moreover, this philosophy, which is the investigation of the first causes
of things, is the most truly educative among the sciences. For instructors
are persons who show us the causes of things. And knowledge for the sake of
knowledge belongs most properly to that inquiry which deals with what is
most truly a matter of knowledge. For he who is seeking knowledge for its
own sake will choose to have that knowledge which most truly deserves the
name, the knowledge, namely, of what most truly appertains to knowledge. Now
the things that most truly appertain to knowledge are the first causes; for
in virtue of one’s possession of these, and by deduction from these, all
else comes to be known; we do not come to know them through what is inferior
to them and underlying them... . The wise man ought therefore to know not
only those things which are the outcome and product of first causes, he must
be possessed of the truth as to the first causes themselves. And wisdom
indeed is just this thoughtful science, a science of what is highest, not
truncated of its head.”
“To the man, therefore, who has in fullest measure this knowledge of
universals, all knowledge must lie to hand; for in a way he knows all that
underlies them. Yet in a sense these universals are what men find hardest to
apprehend, because they stand at the furthest extremity from the perceptions
of sense.”