, is the beginning and
cause of all the passions. Since then the cause is more powerful than
its effect, it seems that anger is not the chief cause of fervor.

Obj. 2: Further, those things which, of themselves, arouse fervor,
increase as time goes on; thus love grows stronger the longer it
lasts. But in course of time anger grows weaker; for the Philosopher
says (Rhet. ii, 3) that "time puts an end to anger." Therefore fervor
is not the proper effect of anger.

Obj. 3: Further, fervor added to fervor produces greater fervor. But
"the addition of a greater anger banishes already existing anger," as
the Philosopher says (Rhet. ii, 3). Therefore anger does not cause
fervor.

_On the contrary,_ Damascene says (De Fide Orth. ii, 16) that "anger
is fervor of the blood around the heart, resulting from an exhalation
of the bile."

_I answer that,_ As stated above (Q. 44, A. 1), the bodily
transmutation that occurs in the passions of the soul is
proportionate to the movement of the appetite. Now it is evident that
every appetite, even the natural appetite, tends with greater force
to repel that which is contrary to it, if it be present: hence we see
that hot water freezes harder, as though the cold acted with greater
force on the hot object. Since then the appetitive movement of anger
is caused by some injury inflicted, as by a contrary that is present;
it follows that the appetite tends with great force to repel the
injury by the desire of vengeance; and hence ensues great vehemence
and impetuosity in the movement of anger. And because the movement of
anger is not one of recoil, which corresponds to the action of cold,
but one of prosecution, which corresponds to the action of heat, the
result is that the movement of anger produces fervor of the blood and
vital spirits around the heart, which is the instrument of the soul's
passions. And hence it is that, on account of the heart being so
disturbed by anger, those chiefly who are angry betray signs thereof
in their outer members. For, as Gregory says (Moral. v, 30) "the
heart that is inflamed with the stings of its own anger beats quick,
the body trembles, the tongue stammers, the countenance takes fire,
the eyes grow fierce, they that are well known are not recognized.
With the mouth indeed he shapes a sound, but the understanding knows
not what it says."

Reply Obj. 1: "Love itself is not felt so keenly as in the absence of
the beloved," as Augustine observes (De Trin.