"All men have a natural desire for knowledge."

The moderation of this desire pertains to the virtue of studiousness;
wherefore it follows that studiousness is a potential part of
temperance, as a subordinate virtue annexed to a principal virtue.
Moreover, it is comprised under modesty for the reason given above
(Q. 160, A. 2).

Reply Obj. 1: Prudence is the complement of all the moral virtues, as
stated in _Ethic._ vi, 13. Consequently, in so far as the knowledge
of prudence pertains to all the virtues, the term "studiousness,"
which properly regards knowledge, is applied to all the virtues.

Reply Obj. 2: The act of a cognitive power is commanded by the
appetitive power, which moves all the powers, as stated above (I-II,
Q. 9, A. 1). Wherefore knowledge regards a twofold good. One is
connected with the act of knowledge itself; and this good pertains to
the intellectual virtues, and consists in man having a true estimate
about each thing. The other good pertains to the act of the
appetitive power, and consists in man's appetite being directed
aright in applying the cognitive power in this or that way to this or
that thing. And this belongs to the virtue of seriousness. Wherefore
it is reckoned among the moral virtues.

Reply Obj. 3: As the Philosopher says (Ethic. ii, 93) in order to be
virtuous we must avoid those things to which we are most naturally
inclined. Hence it is that, since nature inclines us chiefly to fear
dangers of death, and to seek pleasures of the flesh, fortitude is
chiefly commended for a certain steadfast perseverance against such
dangers, and temperance for a certain restraint from pleasures of the
flesh. But as regards knowledge, man has contrary inclinations. For
on the part of the soul, he is inclined to desire knowledge of
things; and so it behooves him to exercise a praiseworthy restraint
on this desire, lest he seek knowledge immoderately: whereas on the
part of his bodily nature, man is inclined to avoid the trouble of
seeking knowledge. Accordingly, as regards the first inclination
studiousness is a kind of restraint, and it is in this sense that it
is reckoned a part of temperance. But as to the second inclination,
this virtue derives its praise from a certain keenness of interest in
seeking knowledge of things; and from this it takes its name. The
former is more essential to this virtue than the latter: since the
desire to know directly regards knowledge, to which studiousness is