SECOND ARTICLE [I-II, Q. 61, Art. 5]

Whether There Are Four Cardinal Virtues?

Objection 1: It would seem that there are not four cardinal virtues.

For prudence is the directing principle of the other moral virtues,

as is clear from what has been said above (Q. 58, A. 4). But that

which directs other things ranks before them. Therefore prudence

alone is a principal virtue.

Obj. 2: Further, the principal virtues are, in a way, moral virtues.

Now we are directed to moral works both by the practical reason, and

by a right appetite, as stated in _Ethic._ vi, 2. Therefore there are

only two cardinal virtues.

Obj. 3: Further, even among the other virtues one ranks higher than

another. But in order that a virtue be principal, it needs not to

rank above all the others, but above some. Therefore it seems that

there are many more principal virtues.

_On the contrary,_ Gregory says (Moral. ii): "The entire structure of

good works is built on four virtues."

_I answer that,_ Things may be numbered either in respect of their

formal principles, or according to the subjects in which they are:

and either way we find that there are four cardinal virtues.

For the formal principle of the virtue of which we speak now is good

as defined by reason; which good is considered in two ways. First, as

existing in the very act of reason: and thus we have one principal

virtue, called "Prudence." Secondly, according as the reason puts its

order into something else; either into operations, and then we have

"Justice"; or into passions, and then we need two virtues. For the

need of putting the order of reason into the passions is due to their

thwarting reason: and this occurs in two ways. First, by the passions

inciting to something against reason, and then the passions need a

curb, which we call "Temperance." Secondly, by the passions

withdrawing us from following the dictate of reason, e.g. through

fear of danger or toil: and then man needs to be strengthened for

that which reason dictates, lest he turn back; and to this end there

is "Fortitude."

In like manner, we find the same number if we consider the subjects

of virtue. For there are four subjects of the virtue we speak of now:

viz. the power which is rational in its essence, and this is

perfected by "Prudence"; and that which is rational by participation,

and is threefold, the will, subject of "Justice," the concupiscible

faculty, subject of "Temperance," and the irascible faculty, subject

of "Fortitude."

Reply Obj. 1: Prudence is the principal of all the virtues simply.

The others are principal, each in its own genus.

Reply Obj. 2: That part of the soul which is rational by

participation is threefold, as stated above.

Reply Obj. 3: All the other virtues among which one ranks before

another, are reducible to the above four, both as to the subject and

as to the formal principle.

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Summa Theologica, Part I-II (Pars Prima Secundae) From the Complete American Edition · 第 397 / 746 题