Liars ... when they speak the truth they are not believed.

What is the essence of life? To serve others and to do good. Often given as a saying of Aristotle with no reference.

Hope is the dream of a waking man.

There is only one way to avoid criticism: do nothing, say nothing and be nothing.

A friend is one soul abiding in two bodies. p. 188; also reported in various sources as:Friendship is a single soul dwelling in two bodies. A true friend is one soul in two bodies. Love is composed of a single soul inhabiting two bodies. What is a friend? A single soul dwelling in two bodies.

Tolerance and apathy are the last virtues of a dying society.

The single harmony produced by all the heavenly bodies singing and dancing together springs from one source and ends by achieving one purpose, and has rightly bestowed the name not of "disordered" but of "ordered universe" upon the whole.

For the purposes of poetry a convincing impossibility is preferable to an unconvincing possibility.

Remember that time slurs over everything, let all deeds fade, blurs all writings and kills all memories. Except are only those which dig into the hearts of men by love.

The roots of education ... are bitter, but the fruit is sweet.

It is the mark of an educated mind to be able to entertain a thought without accepting it.

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

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.

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.

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

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 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.

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.

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.

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.

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 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.

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

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.

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

[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.

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.

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.

.... 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.

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.

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.

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.

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.

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.

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

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.

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.

The science which has to do with nature clearly concerns itself for the most part with bodies and magnitudes and their properties and movements, but also with the principles of this sort of substance, as many as they may be.

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.

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.