ng for Unity Is a Cause of Sorrow?

Objection 1: It would seem that the craving for unity is not a cause
of sorrow. For the Philosopher says (Ethic. x, 3) that "this
opinion," which held repletion to be the cause of pleasure, and
division [*Aristotle wrote _endeian_, 'want'; St. Thomas, in the
Latin version, read 'incisionem'; should he have read
'indigentiam'?], the cause of sorrow, "seems to have originated in
pains and pleasures connected with food." But not every pleasure or
sorrow is of this kind. Therefore the craving for unity is not the
universal cause of sorrow; since repletion pertains to unity, and
division is the cause of multitude.

Obj. 2: Further, every separation is opposed to unity. If therefore
sorrow were caused by a craving for unity, no separation would be
pleasant: and this is clearly untrue as regards the separation of
whatever is superfluous.

Obj. 3: Further, for the same reason we desire the conjunction of
good and the removal of evil. But as conjunction regards unity, since
it is a kind of union; so separation is contrary to unity. Therefore
the craving for unity should not be reckoned, rather than the craving
for separation, as causing sorrow.

_On the contrary,_ Augustine says (De Lib. Arb. iii, 23), that "from
the pain that dumb animals feel, it is quite evident how their souls
desire unity, in ruling and quickening their bodies. For what else is
pain but a feeling of impatience of division or corruption?"

_I answer that,_ Forasmuch as the desire or craving for good is
reckoned as a cause of sorrow, so must a craving for unity, and love,
be accounted as causing sorrow. Because the good of each thing
consists in a certain unity, inasmuch as each thing has, united in
itself, the elements of which its perfection consists: wherefore the
Platonists held that _one_ is a principle, just as _good_ is. Hence
everything naturally desires unity, just as it desires goodness: and
therefore, just as love or desire for good is a cause of sorrow, so
also is the love or craving for unity.

Reply Obj. 1: Not every kind of union causes perfect goodness, but
only that on which the perfect being of a thing depends. Hence
neither does the desire of any kind of unity cause pain or sorrow, as
some have maintained: whose opinion is refuted by the Philosopher
from the fact that repletion is not always pleasant; for instance,
when a man has eaten to repletion, he takes no further pleasure in
eating; because