Reply Obj. 2: Even when it is not an operation, but the effect of an operation, that is the end, this effect is pleasant in so far as possessed or effected: and this implies use or operation.
Reply Obj. 3: Operations are pleasant, in so far as they are proportionate and connatural to the agent. Now, since human power is finite, operation is proportionate thereto according to a certain measure. Wherefore if it exceed that measure, it will be no longer proportionate or pleasant, but, on the contrary, painful and irksome. And in this sense, leisure and play and other things pertaining to repose, are pleasant, inasmuch as they banish sadness which results from labor. ________________________
SECOND ARTICLE [I-II, Q. 32, Art. 2]
Whether Movement Is a Cause of Pleasure?
Objection 1: It would seem that movement is not a cause of pleasure. Because, as stated above (Q. 31, A. 1), the good which is obtained and is actually possessed, is the cause of pleasure: wherefore the Philosopher says (Ethic. vii, 12) that pleasure is not compared with generation, but with the operation of a thing already in existence. Now that which is being moved towards something has it not as yet; but, so to speak, is being generated in its regard, forasmuch as generation or corruption are united to every movement, as stated in Phys. viii, 3. Therefore movement is not a cause of pleasure.
Obj. 2: Further, movement is the chief cause of toil and fatigue in our works. But operations through being toilsome and fatiguing are not pleasant but disagreeable. Therefore movement is not a cause of pleasure.
Obj. 3: Further, movement implies a certain innovation, which is the opposite of custom. But things "which we are accustomed to, are pleasant," as the Philosopher says (Rhet. i, 11). Therefore movement is not a cause of pleasure.
On the contrary, Augustine says (Confess. viii, 3): "What means this, O Lord my God, whereas Thou art everlasting joy to Thyself, and some things around Thee evermore rejoice in Thee? What means this, that this portion of things ebbs and flows alternately displeased and reconciled?" From these words we gather that man rejoices and takes pleasure in some kind of alterations: and therefore movement seems to cause pleasure.
I answer that, Three things are requisite for pleasure; two, i.e. the one that is pleased and the pleasurable object conjoined to him; and a third, which is knowledge of this conjunction: and in respect of these three, movement is pleasant, as the Philosopher says (Ethic. vii, 14 and Rhetor. i, 11). For as far as we who feel pleasure are concerned, change is pleasant to us because our nature is changeable: for which reason that which is suitable to us at one time is not suitable at another; thus to warm himself at a fire is suitable to man in winter but not in summer. Again, on the part of the pleasing good which is united to us, change is pleasant. Because the continued action of an agent increases its effect: thus the longer a person remains near the fire, the more he is warmed and dried. Now the natural mode of being consists in a certain measure; and therefore when the continued presence of a pleasant object exceeds the measure of one's natural mode of being, the removal of that object becomes pleasant. On the part of the knowledge itself (change becomes pleasant), because man desires to know something whole and perfect: when therefore a thing cannot be apprehended all at once as a whole, change in such a thing is pleasant, so that one part may pass and another succeed, and thus the whole be perceived. Hence Augustine says (Confess. iv, 11): "Thou wouldst not have the syllables stay, but fly away, that others may come, and thou hear the whole. And so whenever any one thing is made up of many, all of which do not exist together, all would please collectively more than they do severally, if all could be perceived collectively."
If therefore there be any thing, whose nature is unchangeable; the natural mode of whose being cannot be exceeded by the continuation of any pleasing object; and which can behold the whole object of its delight at once—to such a one change will afford no delight. And the more any pleasures approach to this, the more are they capable of being continual.