The least initial deviation from the truth is multiplied later a thousandfold.

In cases of this sort, let us say adultery, rightness and wrongness do not depend on committing it with the right woman at the right time and in the right manner, but the mere fact of committing such action at all is to do wrong.

It is necessary that every thing which is harmonized, should be generated from that which is void of harmony, and that which is void of harmony from that which is harmonized. ...But there is no difference, whether this is asserted of harmony, or of order, or composition... the same reason will apply to all of these.

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.

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.

It is simplicity that makes the uneducated more effective than the educated when addressing popular audiences.

[I]t'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. ...[T]he 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.

For the things we have to learn before we can do, we learn by doing.

Of things said without any combination, each signifies either substance or quantity or qualification or a relative or where or when or being-in-a-position or having or doing or being affected. To give a rough idea, examples of substance are man, horse; of quantity: four-foot, five-foot; of qualification: white, grammatical; of a relative: double, half, larger; of where: in the Lyceum, in the market-place; of when: yesterday, last-year; of being-in-a-position: is-lying, is sitting; of having: has-shoes-on, has-armour-on; of doing: cutting, burning; of being-affected: being-cut, being-burned.

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.

For well-being and health, again, the homestead should be airy in summer, and sunny in winter. A homestead possessing these qualities would be longer than it is deep; and its main front would face the south.

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.

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.

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.

That body is heavier than another which, in an equal bulk, moves downward quicker.

Therefore only an utterly senseless person can fail to know that our characters are the result of our conduct.

The ancient philosophers... all of them assert that the elements, and those things which are called by them principles, are contraries, though they establish them without reason, as if they were compelled to assert this by truth itself. They differ, however... that some of them assume prior, and others posterior principles; and some of them things more known according to reason, but others such as are more known according to sense: for some establish the hot and the cold, others the moist and the dry, others the odd and the even, and others strife and friendship, as the causes of generation. ...in a certain respect they assert the same things, and speak differently from each other. They assert different things... but the same things, so far as they speak analogously. For they assume principles from the same co-ordination; since, of contraries, some contain, and others are contained.

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.

The third kind of life is the life of contemplation.

A tragedy, then, is the imitation of an action that is serious and also, as having magnitude, complete in itself; in language ... not in a narrative form; with incidents arousing pity and fear, wherewith to accomplish its catharsis of such emotions.

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.

For legislators make the citizens good by forming habits in them, and this is the wish of every legislator, and those who do not effect it miss their mark, and it is in this that a good constitution differs from a bad one.

Knowledge of the fact differs from knowledge of the reason for the fact.

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.

Rhetoric is the counterpart of Dialectic. Both alike are concerned with such things as come, more or less, within the general ken of all men and belong to no definite science. Accordingly, all men make use, more or less, of both; for to a certain extent all men attempt to discuss statements and to maintain them, to defend themselves and to attack others.

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

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

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

It is not necessary to ask whether soul and body are one, just as it is not necessary to ask whether the wax and its shape are one, nor generally whether the matter of each thing and that of which it is the matter are one. For even if one and being are spoken of in several ways, what is properly so spoken of is the actuality.

When people are friends, they have no need of justice, but when they are just, they need friendship in addition.

Universal is known according to reason, but that which is particular, according to sense...

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.

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.

A whole is that which has beginning, middle, and end.

[T]he infinite is in capacity. That, however, which is infinite in capacity is not to be assumed as that which is infinite in energy. ...[I]t has its being in capacity, and in division and diminution. ...[I]t 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.

.... In a word, acts of any kind produce habits or characters of the same kind. Hence we ought to make sure that our acts are of a certain kind; for the resulting character varies as they vary. It makes no small difference, therefore, whether a man be trained in his youth up in this way or that, but a great difference, or rather all the difference.

We may assume the superiority ceteris paribus [all things being equal] of the demonstration which derives from fewer postulates or hypotheses—in short from fewer premisses; for... given that all these are equally well known, where they are fewer knowledge will be more speedily acquired, and that is a desideratum. The argument implied in our contention that demonstration from fewer assumptions is superior may be set out in universal form...

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 is absurd to hold that a man ought to be ashamed of being unable to defend himself with his limbs but not of being unable to defend himself with reason when the use of reason is more distinctive of a human being than the use of his limbs.

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. ...[A]ll 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.

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

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.

But voice is a certain sound of that which is animated; for nothing inanimate emits a voice; but they are said to emit a voice from similitude, as a pipe, and a lyre, and such other inanimate things, have extension, modulation, and dialect; for thus it appears, because voice, also, has these.

The best friend is he that, when he wishes a person's good, wishes it for that person's own sake.

This opinion... appears to be ancient... that the one, excess and defect, are the principles of things... It is not... probable that there are more than three principles... [E]ssence is one certain genus of being: so that principles will differ from each other in prior and posterior alone, but not in genus, for in one genus there is always one contrariety, and all contrarieties appear to be referred to one. That there is neither one element, therefore, nor more than two or three, is evident.

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 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.

But the greatest thing by far is to have a command of metaphor. This alone cannot be imparted by another; it is the mark of genius, for to make good metaphors implies an eye for resemblances.

Plato... introduces two infinities, because both in increase and diminution there appears to be transcendency, and a progression to infinity. Though... he did not use them: for neither is there infinity in numbers by diminution or division; since unity is a minimum: nor by increase; for he extends number as far as to the decad.

It is well said, then, that it is by doing just acts that the just man is produced, and by doing temperate acts the temperate man; without doing these no one would have even a prospect of becoming good. But most people do not do these, but take refuge in theory and think they are being philosophers and will become good in this way, behaving somewhat like patients who listen attentively to their doctors, but do none of the things they are ordered to do.