Reply Obj. 2:  Desire includes a certain expansion arising from the imagination of the thing desired; but this expansion increases at the presence of the pleasurable object:  because the mind surrenders itself more to that object when it is already taking pleasure in it, than when it desires it before possessing it; since pleasure is the end of desire.

Reply Obj. 3:  He that takes pleasure in a thing holds it fast, by clinging to it with all his might:  but he opens his heart to it that he may enjoy it perfectly. ________________________

SECOND ARTICLE [I-II, Q. 33, Art. 2]

Whether Pleasure Causes Thirst or Desire for Itself?

Objection 1:  It would seem that pleasure does not cause desire for itself.  Because all movement ceases when repose is reached.  But pleasure is, as it were, a certain repose of the movement of desire, as stated above (Q. 23, A. 4; Q. 25, A. 2).  Therefore the movement of desire ceases when pleasure is reached.  Therefore pleasure does not cause desire.

Obj. 2:  Further, a thing does not cause its contrary.  But pleasure is, in a way, contrary to desire, on the part of the object:  since desire regards a good which is not yet possessed, whereas pleasure regards the good that is possessed.  Therefore pleasure does not cause desire for itself.

Obj. 3:  Further, distaste is incompatible with desire.  But pleasure often causes distaste.  Therefore it does not cause desire.

On the contrary, Our Lord said (John 4:13):  “Whosoever drinketh of this water, shall thirst again”:  where, according to Augustine (Tract. xv in Joan.), water denotes pleasures of the body.

I answer that, Pleasure can be considered in two ways; first, as existing in reality; secondly, as existing in the memory.  Again thirst, or desire, can be taken in two ways; first, properly, as denoting a craving for something not possessed; secondly, in general, as excluding distaste.

Considered as existing in reality, pleasure does not of itself cause thirst or desire for itself, but only accidentally; provided we take thirst or desire as denoting a craving for some thing not possessed:  because pleasure is an emotion of the appetite in respect of something actually present.  But it may happen that what is actually present is not perfectly possessed:  and this may be on the part of the thing possessed, or on the part of the possessor.  On the part of the thing possessed, this happens through the thing possessed not being a simultaneous whole; wherefore one obtains possession of it successively, and while taking pleasure in what one has, one desires to possess the remainder:  thus if a man is pleased with the first part of a verse, he desires to hear the second part, as Augustine says (Confess. iv, 11).  In this way nearly all bodily pleasures cause thirst for themselves, until they are fully realized, because pleasures of this kind arise from some movement: