e to indicate,
more or less fully, those intellectual excellences, whereby alone we
are enabled to overcome the inherent difficulties of right ethical
conduct; and he indicates them in the present Book, comparing them with
those other intellectual excellences which guide our theoretical
investigations, where conduct is not directly concerned.

In specifying the ethical excellences, or excellences of disposition,
we explained that each of them aimed to realize a mean--and that this
mean was to be determined by Right Reason. To find the mean, is thus an
operation of the Intellect; and we have now to explain what the right
performance of it is,--or to enter upon the Excellences of the
Intellect. The soul having been divided into Irrational and Rational,
the Rational must farther be divided into two parts,--the Scientific
(dealing with necessary matter), the Calculative, or Deliberative
(dealing with contingent matter). We must touch, upon the excellence or
best condition of both of them (I). There are three principal functions
of the soul--Sensation, Reason, and Appetite or Desire. Now, Sensation
(which beasts have as well as men) is not a principle of moral action.
The Reason regards truth and falsehood only; it does not move to
action, it is not an end in itself. Appetite or Desire, which aims at
an end, introduces us to moral action. Truth and Falsehood, as regards
Reason, correspond to Good and Evil as regards Appetite: Affirmation
and Negation, with the first, are the analogues of Pursuit and
Avoidance, with the second. In purpose, which is the principle of moral
action, there is included deliberation or calculation. Reason and
Appetite are thus combined: Good Purpose comprises both true
affirmation and right pursuit: you may call it either an Intelligent
Appetite, or an Appetitive Intelligence. Such is man, as a principle of
action [hae toiautae archae anthropos].

Science has to do with the necessary and the eternal; it is teachable,
but teachable always from _praecognita_, or principles, obtained by
induction; from which principles, conclusions are demonstrated by
syllogism (III.). Art, or Production, is to be carefully distinguished
from the action or agency that belongs to man as an ethical agent, and
that does not terminate in any separate assignable product. But both
the one and the other deal with contingent matters only. Art deals for
the most part with the same matters as are subject to the intervention
of