no need for man to proceed to acts of external penance. This,
however, does not prevent penance being continual, as explained above.

Reply Obj. 2: Of sorrow and joy we may speak in two ways: first, as
being passions of the sensitive appetite; and thus they can nowise
be together, since they are altogether contrary to one another,
either on the part of the object (as when they have the same object),
or at least on the part of the movement, for joy is with expansion
[*Cf. I-II, Q. 33, A. 1] of the heart, whereas sorrow is with
contraction; and it is in this sense that the Philosopher speaks in
_Ethic._ ix. Secondly, we may speak of joy and sorrow as being simple
acts of the will, to which something is pleasing or displeasing.
Accordingly, they cannot be contrary to one another, except on the
part of the object, as when they concern the same object in the same
respect, in which way joy and sorrow cannot be simultaneous, because
the same thing in the same respect cannot be pleasing and
displeasing. If, on the other hand, joy and sorrow, understood thus,
be not of the same object in the same respect, but either of
different objects, or of the same object in different respects, in
that case joy and sorrow are not contrary to one another, so that
nothing hinders a man from being joyful and sorrowful at the same
time--for instance, if we see a good man suffer, we both rejoice at
his goodness and at the same time grieve for his suffering. In this
way a man may be displeased at having sinned, and be pleased at his
displeasure together with his hope for pardon, so that his very
sorrow is a matter of joy. Hence Augustine says [*De vera et falsa
Poenitentia, the authorship of which is unknown]: "The penitent
should ever grieve and rejoice at his grief."

If, however, sorrow were altogether incompatible with joy, this would
prevent the continuance, not of habitual penance, but only of actual
penance.

Reply Obj. 3: According to the Philosopher (Ethic. ii, 3, 6, 7, 9) it
belongs to virtue to establish the mean in the passions. Now the
sorrow which, in the sensitive appetite of the penitent, arises from
the displeasure of his will, is a passion; wherefore it should be
moderated according to virtue, and if it be excessive it is sinful,
because it leads to despair, as the Apostle teaches (2 Cor. 2:7),
saying: "Lest such an one be swallowed up with overmuch sorrow."
Accordingly comfort, of which the Apostle speaks, moderates sorrow