The truly good and wise man will bear all kinds of fortune in a seemly way, and will always act in the noblest manner that the circumstances allow.

There are three lines of life which stand out prominently to view: the life of pleasure, the political life, and the life of reflection.

The majority of mankind and people who lack refinement conceive it to be pleasure, and hence they approve a life of sensual enjoyment.

Now men seem, not unreasonably, to form their notions of the supreme good and of happiness from the lives of men.

As for him who neither possesses nor can acquire them, let him take to heart the words of Hesiod: ‘ He is the best of all who thinks for himself in all things. He, too, is good who takes advice from a wiser (person). But he who neither thinks for himself, nor lays to heart another's wisdom, this is a useless man.’

If a man knows what it is right to do, he does not require a formal reason. And a person that has been thus trained, either possesses these first principles already, or can easily acquire them.

Perhaps then we must begin with such facts as are known to us from individual experience. It is necessary therefore that the person who is to study, with any tolerable chance of profit, the principles of nobleness and justice and politics generally, should have received a good moral training.

And surely to know what this good is, is of great importance for the conduct of life, for in that case we shall be like archers shooting at a definite mark, and shall be more likely to do what is right. But, if this is the case, we must try to comprehend, in outline at least, what it is and to which of the sciences it belongs.

If, then, in the sphere of action there is some one end which we desire for its own sake, and for the sake of which we desire every thing else; and if we do not choose every thing for the sake of something else, for this would go on without limit, and our desire would be idle and futile, it is clear that this must be the supreme good, and the best thing of all.

But it is clear there is a difference in the ends proposed: for in some cases they are activities, and in others results beyond the mere activities, and where there are certain ends beyond and beside the actions, the results are naturally superior to the activities. Now, as there are numerous kinds of actions and numerous arts and sciences, it follows that the ends are also various. Thus the end of the healing art is health, of ship-building ships, of strategy victory, of economy wealth.

Every art, and every system, and in like manner every action and purpose aims, it is thought, at some good; for which reason a common and by no means a bad description of the good is, ‘that at which all things aim.’

Those who assert that the mathematical sciences say nothing of the beautiful or the good are in error. For these sciences say and prove a great deal about them; if they do not expressly mention them, but prove attributes which are their results or definitions, it is not true that they tell us nothing about them. The chief forms of beauty are order and symmetry and definiteness, which the mathematical sciences demonstrate in a special degree.

That which is desirable on its own account and for the sake of knowing it is more of the nature of wisdom than that which is desirable on account of its results.

Now the mass of mankind are plainly... choosing a life like that of brute animals...

The refined and active, on the other hand, prefer honour, which I suppose may be said to be the end of the political life. Yet honour is plainly too superficial to be the object of our search, because it appears to depend rather on those who give than on those who receive it, whereas we feel instinctively that the good must be something proper to a man, which cannot easily be taken from him.

Men seem to pursue honour in order that they may believe themselves to be good. Accordingly, they seek to be honoured by the wise, and by those who know them well, and on the score of virtue; it is clear, therefore, that in their opinion at any rate, virtue is superior to honour. Perhaps, then, one ought to say that virtue rather than honour is the end of the political life; yet even virtue is plainly too imperfect: for it seems that a man might have all the virtues and yet be asleep, or fail to achieve anything all his life; moreover, such a person may suffer the greatest evils and misfortunes. And no one, in this case, would call a man, who passed his life in this manner, happy, except for argument's sake.

Everything that depends on the action of nature is by nature as good as it can be, and similarly everything that depends on art or any rational cause, and especially if it depends on the best of all causes. To entrust to chance what is greatest and most noble would be a very defective arrangement.

For some identify happiness with virtue, some with practical wisdom, others with a kind of philosophic wisdom, others with these, or one of these, accompanied by pleasure or not without pleasure; while others include also external prosperity. Now ... it is not probable that these should be entirely mistaken, but rather that they should be right in at least some one respect or even in most respects.

Let this serve as an outline of the good; for we must presumably first sketch it roughly, and then later fill in the details. But it would seem that any one is capable of carrying on and articulating what has once been well outlined, and that time is a good discoverer or partner in such a work; to which facts the advances of the arts are due; for any one can add what is lacking. And we must also remember what has been said before, and not look for precision in all things alike, but in each class of things such precision as accords with the subject-matter, and so much as is appropriate to the inquiry. For a carpenter and a geometer investigate the right angle in different ways; the former does so in so far as the right angle is useful for his work, while the latter inquires what it is or what sort of thing it is; for he is a spectator of the truth. We must act in the same way, then, in all other matters as well, that our main task may not be subordinated to minor questions. Nor must we demand the cause in all matters alike; it is enough in some cases that the fact be well established, as in the case of the first principles; the fact is the primary thing or first principle. Now of first principles we see some by induction, some by perception, some by a certain habituation, and others too in other ways. But each set of principles we must try to investigate in the natural way, and we must take pains to state them definitely, since they have a great influence on what follows. For the beginning is thought to be more than half of the whole, and many of the questions we ask are cleared up by it.

Life seems to be common even to plants, but we are seeking what is peculiar to man. Let us exclude, therefore, the life of nutrition and growth. Next there would be a life of perception, but it also seems to be common even to the horse, the ox, and every animal. There remains, then, an active life of the element that has a rational principle; of this, one part has such a principle in the sense of being obedient to one, the other in the sense of possessing one and exercising thought. And, as "life of the rational element" also has two meanings, we must state that life in the sense of activity is what we mean; for this seems to be the more proper sense of the term. Now if the function of man is an activity of soul which follows or implies a rational principle, and if we say "so-and-so" and "a good so-and-so" have a function which is the same in kind, e.g. a lyre, and a good lyre-player, and so without qualification in all cases, eminence in respect of goodness being added to the name of the function (for the function of a lyre-player is to play the lyre, and that of a good lyre-player is to do so well): if this is the case, and we state the function of man to be a certain kind of life, and this to be an activity or actions of the soul implying a rational principle, and the function of a good man to be the good and noble performance of these, and if any action is well performed when it is performed in accordance with the appropriate excellence: if this is the case, human good turns out to be activity of soul in accordance with virtue, and if there are more than one virtue, in accordance with the best and most complete. But we must add "in a complete life." For one swallow does not make a summer, nor does one day; and so too one day, or a short time, does not make a man blessed and happy.

While both are dear, Piety requires us to honor truth above our friends.

The life of money-making is one undertaken under compulsion, and wealth is evidently not the good we are seeking; for it is merely useful and for the sake of something else.

It is the mark of an educated man to look for precision in each class of things just so far as the nature of the subject admits; it is evidently equally foolish to accept probable reasoning from a mathematician and to demand from a rhetorician scientific proofs.

If there is some end of the things we do, which we desire for its own sake, clearly this must be the good. Will not knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what we should? If so, we must try, in outline at least, to determine what it is.

A person might fairly doubt also what in the world they mean by the ‘absolute’ this that or the other, since, as they would themselves allow, the account of the humanity is one and the same in the absolute man, and in any individual man: for so far as the individual and the absolute man are both man, they will not differ at all: and if so, then the essential good and any particular good will not differ, in so far as both are good. Nor will it do to say that the eternity of the absolute good makes it to be more good; for a white thing which has lasted white ever so long, is no whiter than that which only lasts for a day.

But it is better perhaps to examine next the universal good, and to enquire in what sense the expression is used. Though such an investigation is likely to be difficult, because the persons who have introduced these ideas are our friends. Yet it will perhaps appear the best, and indeed the right course, at least for the preservation of truth, to do away with private feelings, especially as we are philosophers; for since both are dear to us, we are bound to prefer the truth.

As for the life of money-making, it is one of constraint, and wealth is manifestly not the good of which we are in search, for it is only useful as a means to something else, and for this reason there is less to be said for it than for the ends mentioned before, which are, at any rate, desired for their own sakes.

The third kind of life is the life of contemplation.

For it is owing to their wonder that men both now begin and at first began to philosophize; they wondered originally at the obvious difficulties, then advanced little by little and stated difficulties about the greater matters, e.g. about the phenomena of the moon and those of the sun and of the stars, and about the genesis of the universe. And a man who is puzzled and wonders thinks himself ignorant (whence even the lover of myth is in a sense a lover of Wisdom, for the myth is composed of wonders); therefore since they philosophized order to escape from ignorance, evidently they were pursuing science in order to know, and not for any utilitarian end.

All men by nature desire to know. An indication of this is the delight we take in our senses; for even apart from their usefulness they are loved for themselves; and above all others the sense of sight. For not only with a view to action, but even when we are not going to do anything, we prefer sight to almost everything else. The reason is that this, most of all the senses, makes us know and brings to light many differences between things.

Music directly represents the passion of the soul. If one listens to the wrong kind of music, he will become the wrong kind of person.

It's gravity is the cause; and that which is heavy abides in the middle, and the earth is in the middle: in like manner also, the infinite will abide in itself, through some other cause... and will itself support itself. ...The places of the whole and the part are of the same species; as of the whole earth and a clod, the place is downward; and of the whole of fire, and a spark, the place is upward. So that if the place of the infinite is in itself, there will be the same place also of a part of the infinite.

It is impossible that each of the elements should be infinite. For that is body which has interval on all sides; and that is infinite which has extension without bound.

They pronounce absurdly who thus speak, as the Pythagoreans assert: for at the same time they make the infinite to be essence, and distribute it into parts.

Because that which is finite is always bounded with reference to something... it is necessary that there should be no end... Number also appears to be infinite, and mathematical magnitudes, and that which is beyond the heavens. And since that which is beyond is infinite, body also appears to be infinite, and it would seem that there are infinite worlds; for why is there rather void here than there? ...If also there is a vacuum, and an infinite place, it is necessary that there should be an infinite body: for in things which have a perpetual subsistence, capacity differs nothing from being. The speculation of the infinite is, however, attended with doubt: for many impossibilities happen both to those who do not admit that it has a subsistence, and to those who do. ...It is ...especially the province of a natural philosopher to consider if there be a sensible infinite magnitude.

All those... who discourse concerning nature, always subject a certain other nature of... elements, to the infinite... But no one of those who make the elements to be finite introduces infinity. Such, however, as make infinite elements, as Anaxagoras and Democritus, say that the infinite is continuous by contact. ...Rationally, too, do all philosophers consider the infinite as a principle; for it cannot be in vain, nor can any other power be present with it than that of a principle: for all things are either the principle, or from the principle; but of the infinite there is no principle, since otherwise it would have an end. ...it is also unbegotten and uncorruptible, as being a certain principle: for... end is the corruption of everything. ...It likewise appears to comprehend and govern all things, as those assert who do not introduce other causes beside the infinite... It would seem also that this is divine: for it is immortal and indestructible, as Anaximander says, and most of the physiologists.

Since the science of nature is conversant with magnitudes, motion, and time, each of which must necessarily be either infinite or finite...we should speculate the infinite, and consider whether it is or not; and if it is what it is. ...All those who appear to have touched on a philosophy of this kind... consider it as a certain principle of beings. Some, indeed, as the Pythagoreans and Plato, consider it, per se, not as being an accident to any thing else, but as having an essential subsistence... the Pythagoreans... consider the infinite as subsisting in sensibles; for they do not make number to be separate; and they assert that what is beyond the heavens is infinite; but Plato says that beyond the heavens there is not any body, nor ideas, because these are no where: he affirms, however, that the infinite is both in sensibles, and in ideas. ...Plato establishes two infinities, viz. the great and the small.

There is... something which is in energy only; and there is something which is both in energy and capacity. ...of relatives, one is predicated as according to excess and defect: another according to the effective and passive, and, in short, the motive, and that which may be moved... Motion, however, has not a substance separate from things... But each of the categories subsists in a twofold manner in all things. Thus... one thing pertaining to it is form, and another privation. ...So the species of motion and mutation are as many as those of being. But since in every genus of things, there is that which is in entelecheia, and that which is in capacity; motion is the entelecheia of that which is in capacity... That there is energy, therefore, and that a thing then happens to be moved, when this energy exists, and neither prior nor posterior to it, is manifest. ... Neither motion nor mutation can be placed in any other genus; nor have those who have advanced a different opinion concerning it spoken rightly. ...for by some motion is said to be difference, inequality, and non-being; though it is not necessary that any of these should be moved... Neither is mutation into these, nor from these, rather than from their opposites. ...The cause, however, why motion appears to be indefinite, is because it can neither be simply referred to the capacity, nor to the energy of beings. ...It is difficult to apprehend what motion is: for it is necessary to refer it either to privation, or to capacity, or to simple energy; but it does not appear that it can be any of these. The above-mentioned mode, therfore remains, viz. that it is a certain energy; but... difficult to be perceived, but which may have a subsistence.

It is impossible for motion to subsist without place, and void, and time.

Since... nature is a principle of motion and mutation... it is necessary that we should not be ignorant of what motion is... But motion appears to belong to things continuous; and the infinite first presents itself to the view in that which is continuous. ...Frequently ...those who define the continuous, employ the nature or the infinite, as if that which is divisible to infinity is continuous.

Since causes are four in number, to know them all is the business of the natural philosopher, who also referring to the cause why a thing is to all of them, viz. to matter, form, that which moves, and for the sake of which a thing subsists, physically assigns a reason. Frequently, however, three of these causes pass into one: for the cause why a thing is, and that for the sake of which it is, are one. But that which motion first originates, is in species the same with these... There are three treatises; once concerning that which is immoveable; another concerning that which is moved, indeed, but is incorruptible; and a third concerning corruptible natures. So the cause of why a thing is, is assigned by him who refers to matter, to essence, and to the first mover... But there are two principles which are naturally motive; of which, one is not physical, because it does not contain in itself the principle of motion. And if there is any thing which moves without being moved, it is of this kind; as is that which is perfectly immoveable, that which is the first of all things, together with essence and form: for it is the end, and that for the sake of which a thing subsists. So that since nature is for the sake of something, it is also necessary to know this cause.

Fortune... and chance, are said to be in the number of causes... With some it is dubious whether these things have subsistence or not. For, say they, nothing is produced from fortune, but there is a definite cause of all such things... For if fortune were any thing, it would truly appear to be absurd; and some one might doubt why no one of the ancient wise men, when assigning the causes of generation and corruption, has ever defined any thing concerning fortune. ...Many things are produced, and have a subsistence, from fortune and chance... They did not, however, think that fortune was any thing belonging to friendship or strife, or fire, or intellect, or any thing else of things of this kind. They are chargeable, therefore, with absurdity, whether they did not conceive that it had a substance, or whether fancying that it had, they omitted it; especially since it was sometimes employed by them. Thus Empedocles says that the air...Thus it then chanc'd to run, tho' varying oft.He also says that the greater part of... animals were generated by fortune. But there are some who assign chance to the cause of this heaven, and of all mundane natures... We must consider... whether chance or fortune are the same... or different from each other, and how they fall into definite causes.

Let us consider, with respect to causes, what they are, and how many there are in number... this also must be done by us in discoursing concerning generation and corruption, and all physical mutation... knowing the principles of these...Cause... is after one manner said to be that, from which, being inherent, something is produced... But after another manner cause is form and paradigm (and this is the definition of the essence of a thing) and the genera of this. ...But it happens... that there are also many causes of the same thing, and this is not from accident. ...seed, a physician, he who consults, and, in short, he who makes, are all of them causes, as that whence the principle of mutation, or permanency, or motion is derived. ...It is, however, necessary always to investigate the supreme cause of every thing ...Further still, it is necessary to investigate the genera of genera; and the particulars of particulars... We should also explore the capacities of the capabilities, and the energizers of the things affected by energy.

How will one part of the infinite be above, and another below? Or how will it have extremes or a middle? Further still, every sensible body is in place; but the species and differences of place are upward and downward, before and behind, to the right hand and to the left: and these things not only thus subsist with relation to us, and by position, but have a definite subsistence in the universe itself. But it is impossible that these things should be in the infinite: and... that there should be an infinite place. But every body is in place; and therefore it is also impossible that there should be an infinite body. ...Therefore ...there is not an infinite body in energy.

The infinite is in capacity. That, however, which is infinite in capacity is not to be assumed as that which is infinite in energy. ...It has its being in capacity, and in division and diminution. ...It is always possible to assume something beyond it. It does not, however, on this account surpass every definite magnitude; as in division it surpasses every definite magnitude, and will be less.

The infinite... happens to subsist in a way contrary to what is asserted by others: for the infinite is not that beyond which there is nothing, but it is that of which there is always something beyond. ...But that pertaining to which there is nothing beyond is perfect and whole. ...that of which nothing is absent pertaining to the parts ...the whole is that pertaining to which there is nothing beyond. But that pertaining to which something external is absent, that is not all ...But nothing is perfect which has not an end; and the end is a bound. On this account... Parmenides spoke better than Melissus: for the latter says that the infinite is a whole; but the former, that the whole is finite, and equally balanced from the middle: for to conjoin the infinite with the universe and the whole, is not to connect line with line.

Just as it sometimes happens that deformed offspring are produced by deformed parents, and sometimes not, so the offspring produced by a female are sometimes female, sometimes not, but male, because the female is as it were a deformed male.

Concerning the generation of animals akin to them, as hornets and wasps, the facts in all cases are similar to a certain extent, but are devoid of the extraordinary features which characterize bees; this we should expect, for they have nothing divine about them as the bees have.

Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end.

The essential nature (concerning the soul) cannot be corporeal, yet it is also clear that this soul is present in a particular bodily part, and this one of the parts having control over the rest (heart).