We may ascertain the nature and quality of pleasure more clearly if we start again from the beginning. Now the act of sight appears to be perfect at any moment of its duration; it does not require anything to supervene later in order to perfect its specific quality. But pleasure also appears to be a thing of this nature. For it is a whole, and one cannot at any moment put one’s hand on a pleasure which will only exhibit its specific quality perfectly if its duration be prolonged. It follows also that pleasure is not a form of motion.¹ For every motion or process of change involves duration, and is a means to an end, for instance the process of building a house; and it is perfect when it has effected its end. Hence a motion is perfect either when viewed over the whole time of its duration, or at the moment when its end has been achieved. The several motions occupying portions of the time of the whole are imperfect, and different in kind from the whole and from each other. For instance, in building a temple the fitting together of the stones is a different process from the fluting of a column, and both are different from the construction of the temple as a whole; and whereas the building of the temple is a perfect process, for nothing more is required to achieve the end proposed, laying the foundation and constructing the triglyphs are imperfect processes, since each produces only a part of the design; they are therefore specifically different from the construction of the whole, and it is not possible to lay one’s finger on a motion specifically perfect at any moment of the process of building, but only, if at all, in the whole of its duration. And the same is true of walking and the other forms of locomotion. For if locomotion is motion from one point in space to another, and if this is of different kinds, flying, walking, leaping and the like, and not only so, but if there are also differences in walking itself (for the terminal points of a race course are not the same as those of a portion of the course, nor are those of one portion the same as those of another; nor is traversing this line the same as traversing that one,² 1174bfor the runner does not merely travel along a certain line but travels along a line that is in a certain place, and this line is in a different place from that)—however, for a full treatment of the subject of motion I must refer to another work,³ but it appears that a motion is not perfect at every moment, but the many movements which make up the whole are imperfect; and different from each other in kind, inasmuch as the terminal points of a movement constitute a specific quality. The specific quality of pleasure on the contrary is perfect at any moment. It is clear therefore that pleasure is not the same as motion, and that it is a whole and something perfect. This may also be inferred from the fact that a movement necessarily occupies a space of time, whereas a feeling of pleasure does not, for every moment of pleasurable consciousness is a perfect whole. These considerations also show that it is a mistake to speak of pleasure as the result of a motion or of a process of generation. For we cannot so describe everything, but only such things as are divided into parts and are not wholes. Thus an act of sight, a geometrical point, an arithmetical unit are not the result of a process of generation (nor is any of them a motion or process⁴). Pleasure therefore also is not the result of a motion or process; for pleasure is a whole. Again, inasmuch as each of the senses acts in relation to its object, and acts perfectly when it is in good condition and directed to the finest of the and objects that belong to it (for this seems to be the best description of perfect activity, it being assumed to make no difference whether it be the sense itself that acts or the organ in which the sense resides), it follows that the activity of any of the senses is at its best when the sense-organ being in the best condition is directed to the best of its objects; and this activity will be the most perfect and the pleasantest. For each sense has a corresponding pleasure, as also have thought and speculation, and its activity is pleasantest when it is most perfect, and most perfect when the organ is in good condition and when it is directed to the most excellent of its objects; and the pleasure perfects the activity. The pleasure does not however perfect the activity in the same way as the object perceived and the sensory faculty, if good, perfect it; just as health and the physician are not in the same way the cause of being healthy. (It is clear that each of the senses is accompanied by pleasure, since we apply the term pleasant to sights and sounds⁵; and it is also clear that the pleasure is greatest when the sensory faculty is both in the best condition and acting in relation to the best object; and given excellence in the perceived object and the percipient organ, there will always be pleasure when an object to cause it and a subject to feel it are both present.) But the pleasure perfects the activity, not as the fixed disposition does, by being already present in the agent, but as a supervening perfection, like the bloom of health in the young and vigorous. So long therefore as both object thought of or perceived, and subject discerning or judging, are such as they should be, 1175athere will be pleasure in the activity; since while both the passive and the active parties to a relationship remain the same in themselves and unaltered in their relation to one another, the same result is naturally produced. How is it then that no one can feel pleasure continuously? Perhaps it is due to fatigue, since no human faculty is capable of uninterrupted activity, and therefore pleasure also is not continuous, because it accompanies the activity of the faculties. It is for the same reason that some things please us when new, but cease to give so much pleasure later; this is because at first the mind is stimulated, and acts vigorously in regard to the object, as in the case of sight when we look at something intently; but afterwards the activity is less vigorous and our attention relaxes, and consequently the pleasure also fades. It might be held that all men seek to obtain pleasure, because all men desire life. Life is a form of activity, and each man exercises his activity upon those objects and with those faculties which he likes the most: for example, the musician exercises his sense of hearing upon musical tunes, the student his intellect upon problems of philosophy, and so on. And the pleasure of these activities perfects the activities, and therefore perfects life, which all men seek. Men have good reason therefore to pursue pleasure, since it perfects for each his life, which is a desirable thing. The question whether we desire life for the sake of pleasure or pleasure for the sake of life, need not be raised for the present. In any case they appear to be inseparably united; for there is no pleasure without activity, and also no perfect activity without its pleasure.

This moreover is the ground for believing that pleasures vary in specific quality. For we feel that different kinds of things must have a different sort of perfection. We see this to be so with natural organisms and the productions of art, such as animals, trees, a picture, a statue, a house, a piece of furniture. Similarly we think that that which perfects one kind of activity must differ in kind from that which perfects another kind. Now the activities of the intellect differ from those of the senses, and from⁶ one another, in kind: so also therefore do the pleasures that perfect them. This may also be seen from the affinity which exists between the various pleasures and the activities which they perfect. For an activity is augmented by the pleasure that belongs to it; since those who work with pleasure always work with more discernment and with greater accuracy—for instance, students who are fond of geometry become proficient in it, and grasp its various problems better, and similarly lovers of music, architecture or the other arts make progress in their favorite pursuit because they enjoy it. An activity then is augmented by its pleasure; and that which augments a thing must be akin to it. 1175bBut things that are akin to things of different kinds must themselves differ in kind. A still clearer proof may be drawn from the hindrance that activities receive from the pleasure derived from other activities. For instance, persons fond of the flute cannot give their attention to a philosophical discussion when they overhear someone playing the flute, because they enjoy music more than the activity in which they are engaged; therefore the pleasure afforded by the music of the flute impairs the activity of study. The same thing occurs in other cases when a man tries to do two things at once; the pleasanter activity drives out the other, the more so if it is much more pleasant, until the other activity ceases altogether. Hence, when we enjoy something very much, we can hardly do anything else; and when we find a thing only mildly agreeable, we turn to some other occupation; for instance, people who eat sweets at the theater do so especially when the acting is bad. And since our activities are sharpened, prolonged and improved by their own pleasure, and impaired by the pleasures of other activities, it is clear that pleasures differ widely from each other. In fact alien pleasures have almost the same effect on the activities as their own pains⁷; since, when an activity causes pain, this pain destroys it, for instance, if a person finds writing or doing sums unpleasant and irksome; for he stops writing or doing sums, because the activity is painful. Activities then are affected in opposite ways by the pleasures and the pains that belong to them, that is to say, those that are intrinsically due to their exercise. Alien pleasures, as has been said, have very much the same effect as pain, for they destroy an activity, only not to the same degree. Again, since activities differ in moral value, and some are to be adopted, others to be avoided, and others again are neutral, the same is true also of their pleasures: for each activity has a pleasure of its own. Thus the pleasure of a good activity is morally good, that of a bad one morally bad; for even desires for noble things are praised and desires for base things blamed; but the pleasures contained in our activities are more intimately connected with them than the appetites which prompt them, for the appetite is both separate in time and distinct in its nature from the activity, whereas the pleasure is closely linked to the activity, indeed so inseparable from it as to raise a doubt whether the activity is not the same thing as the pleasure. However, we must not regard pleasure as really being a thought or a sensation—indeed this is absurd, though because they are inseparable they seem to some people to be the same. As then activities are diverse, so also are their pleasures. 1176aSight excels touch in purity, and hearing and smell excel taste; and similarly the pleasures of the intellect excel in purity the pleasures of sensation, while the pleasures of either class differ among themselves in purity. And it is thought that every animal has its own special pleasure, just as it has its own special function: namely, the pleasure of exercising that function. This will also appear if we consider the different animals one by one: the horse, the dog, man, have different pleasures—as Heracleitus says, an ass would prefer chaff to gold, since to asses food gives more pleasure than gold. Different species therefore have different kinds of pleasures. On the other hand it might be supposed that there is no variety among the pleasures of the same species. But as a matter of fact in the human species at all events there is a great diversity of pleasures. The same things delight some men and annoy others, and things painful and disgusting to some are pleasant and attractive to others. This also holds good of things sweet to the taste: the same things do not taste sweet to a man in a fever as to one in good health; nor does the same temperature feel warm to an invalid and to a person of robust constitution. The same holds good of other things as well. But we hold that in all such cases the thing really is what it appears to be to the good man. And if this rule is sound, as it is generally held to be, and if the standard of everything is goodness, or the good man, qua good, then the things that seem to him to be pleasures are pleasures, and the things he enjoys are pleasant. Nor need it cause surprise that things disagreeable to the good man should seem pleasant to some men; for mankind is liable to many corruptions and diseases, and the things in question are not really pleasant, but only pleasant to these particular persons, who are in a condition to think them so. It is therefore clear that we must pronounce the admittedly disgraceful pleasures not to be pleasures at all, except to the depraved. But among the pleasures considered respectable, which class of pleasures or which particular pleasure is to be deemed the distinctively human pleasure? Perhaps this will be clear from a consideration of man’s activities. For pleasures correspond to the activities to which they belong; it is therefore that pleasure, or those pleasures, by which the activity, or the activities, of the perfect and supremely happy man are perfected, that must be pronounced human in the fullest sense. The other pleasures are so only in a secondary or some lower degree, like the activities to which they belong.