irtue. Secondly, as regards the
perfect degree of virtue, and as to this virtue may be hindered by
that which is not a sin, but a lesser good. In this way sexual
intercourse casts down the mind not from virtue, but from the height,
i.e. the perfection of virtue. Hence Augustine says (De Bono Conjug.
viii): "Just as that was good which Martha did when busy about
serving holy men, yet better still that which Mary did in hearing the
word of God: so, too, we praise the good of Susanna's conjugal
chastity, yet we prefer the good of the widow Anna, and much more
that of the Virgin Mary."

Reply Obj. 2: As stated above (Q. 152, A. 2, ad 2; I-II, Q. 64, A.
2), the mean of virtue depends not on quantity but on conformity with
right reason: and consequently the exceeding pleasure attaching to a
venereal act directed according to reason, is not opposed to the mean
of virtue. Moreover, virtue is not concerned with the amount of
pleasure experienced by the external sense, as this depends on the
disposition of the body; what matters is how much the interior
appetite is affected by that pleasure. Nor does it follow that the
act in question is contrary to virtue, from the fact that the free
act of reason in considering spiritual things is incompatible with
the aforesaid pleasure. For it is not contrary to virtue, if the act
of reason be sometimes interrupted for something that is done in
accordance with reason, else it would be against virtue for a person
to set himself to sleep. That venereal concupiscence and pleasure are
not subject to the command and moderation of reason, is due to the
punishment of the first sin, inasmuch as the reason, for rebelling
against God, deserved that its body should rebel against it, as
Augustine says (De Civ. Dei xiii, 13).

Reply Obj. 3: As Augustine says (De Civ. Dei xiii, 13), "the child,
shackled with original sin, is born of fleshly concupiscence (which
is not imputed as sin to the regenerate) as of a daughter of sin."
Hence it does not follow that the act in question is a sin, but that
it contains something penal resulting from the first sin.
_______________________

THIRD ARTICLE [II-II, Q. 153, Art. 3]

Whether the Lust That Is About Venereal Acts Can Be a Sin?

Objection 1: It would seem that lust about venereal acts cannot be a
sin. For the venereal act consists in the emission of semen which is
the surplus from food, according to the Philosopher (De Gener. Anim.
i, 18). But there is no