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.

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

And happiness is thought to depend on leisure; for we are busy that we may have leisure, and make war that we may live in peace.

Now the activity of the practical virtues is exhibited in political or military affairs, but the actions concerned with these seem to be unleisurely. Warlike actions are completely so (for no one chooses to be at war, or provokes war, for the sake of being at war; any one would seem absolutely murderous if he were to make enemies of his friends in order to bring about battle and slaughter); but the action of the statesman is also unleisurely, and-apart from the political action itself—aims at despotic power and honours, or at all events happiness, for him and his fellow citizens—a happiness different from political action, and evidently sought as being different. So if among virtuous actions political and military actions are distinguished by nobility and greatness, and these are unleisurely and aim at an end and are not desirable for their own sake, but the activity of reason, which is contemplative, seems both to be superior in serious worth and to aim at no end beyond itself, and to have its pleasure proper to itself (and this augments the activity), and the self-sufficiency, leisureliness, unweariedness (so far as this is possible for man), and all the other attributes ascribed to the supremely happy man are evidently those connected with this activity, it follows that this will be the complete happiness of man, if it be allowed a complete term of life.

Misfortune shows those who are not really friends.

Homer has taught all other poets the art of telling lies skillfully.

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.

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

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.

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

Wit is cultured insolence.

The young have exalted notions, because they have not been humbled by life or learned its necessary limitations; moreover, their hopeful disposition makes them think themselves equal to great things—and that means having exalted notions. They would always rather do noble deeds than useful ones: Their lives are regulated more by moral feeling than by reasoning.... All their mistakes are due to excess and vehemence and their neglect of the maxim of Chilon [The maxim was Μηδὲν ἄγαν, Ne quid nimis, Never go to extremes.]. They overdo everything; they love too much, hate too much, and the same with everything else. And they think they know everything, and confidently affirm it, and this is the cause of their excess in everything.

Thus every action must be due to one or other of seven causes: chance, nature, compulsion, habit, reasoning, anger, or appetite.

Evils draw men together.

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.

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.

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.

May not we then confidently pronounce that man happy who realizes complete goodness in action, and is adequately furnished with external goods? Or should we add, that he must also be destined to go on living not for any casual period but throughout a complete lifetime in the same manner, and to die accordingly, because the future is hidden from us, and we conceive happiness as an end, something utterly and absolutely final and complete? If this is so, we shall pronounce those of the living who possess and are destined to go on possessing the good things we have specified to be supremely blessed, though on the human scale of bliss.

All things as subsist from nature appear to contain in themselves a principle of motion and permanency; some according to place, others according to increase and diminuation; and others according to change in quality.

But as more arts were invented, and some were directed to the necessities of life, others to recreation, the inventors of the latter were naturally always regarded as wiser than the inventors of the former, because their branches of knowledge did not aim at utility. ... This is why the mathematical arts were founded in Egypt; for there the priestly caste was allowed to be at leisure.

I have gained this by philosophy ... I do without being ordered what some are constrained to do by their fear of the law.

Philosophy is the science of truth.

My lectures are published and not published; they will be intelligible to those who heard them, and to none beside.

Nature does not do anything in vain.

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.

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

The premises of demonstrative knowledge must be true, primary, immediate, more knowable than and prior to the conclusion, which is further related to them as effect to cause... The premises must be the cause of the conclusion, more knowable than it, and prior to it; its causes, since we possess scientific knowledge of a thing only when we know its cause; prior, in order to be causes; antecedently known, this antecedent knowledge being not our mere understanding of the meaning, but knowledge of the fact as well. Now 'prior' and 'more knowable' are ambiguous terms, for there is a difference between what is prior and more knowable in the order of being and what is prior and knowable to man. I mean that objects nearer to sense are prior and more knowable to man; objects without qualification prior and more knowable are those further from sense. Now the most universal causes are furthest from sense and particular causes are nearest to sense, and they are thus exactly opposed to each other.

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...

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.

The first philosophers, in investigating the truth and the nature of things, wandered, as if led by ignorance, into a certain... path. Hence, they say that no being is either generated or corrupted, because it is necessary that what is generated should be generated either from being or non-being: but both these are impossible; for neither can being be generated, since it already is; and from nothing, nothing can be generated... And thus... they said that there were not many things, but that being alone had a subsistence. ...the ancient philosophers ...through this ignorance added so much to their want of knowledge, as to fancy that nothing else was generated or had a being; but they subverted all generation.

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.

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

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.

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.

But it is better to assume principles less in number and finite, as Empedocles makes them to be. All philosophers... make principles to be contraries... (for Parmenides makes principles to be hot and cold, and these he demominates fire and earth) as those who introduce as principles the rare and the dense. But Democritus makes the principles to be the solid and the void; of which the former, he says, has the relation of being, and the latter of non-being. ...it is necessary that principles should be neither produced from each other, nor from other things; and that from these all things should be generated. But these requisites are inherent in the first contraries: for, because they are first, they are not from other things; and because they are contraries, they are not from each other.

The natural way of doing this [seeking scientific knowledge or explanation of fact] is to start from the things which are more knowable and obvious to us and proceed towards those which are clearer and more knowable by nature; for the same things are not 'knowable relatively to us' and 'knowable' without qualification. So in the present inquiry we must follow this method and advance from what is more obscure by nature, but clearer to us, towards what is more clear and more knowable by nature. Now what is to us plain and obvious at first is rather confused masses, the elements and principles of which became known to us by later analysis...

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

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

I have gained this by philosophy ... I do without being ordered what some are constrained to do by their fear of the law.

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

Hope is the dream of a waking man.

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.

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.

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.

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

Man is a goal-seeking animal. His life only has meaning if he is reaching out and striving for goals.

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

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

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

The male has more teeth than the female in mankind, and sheep, and goats, and swine. This has not been observed in other animals.