It was a saying of his that education was an ornament in prosperity and a refuge in adversity.

One of the sayings of Diogenes was that most men were within a finger’s breadth of being mad; for if a man walked with his middle finger pointing out, folks would think him mad, but not so if it were his forefinger.

All things are in common among friends.

"Be of good cheer," said Diogenes; "I see land."

A man once asked Diogenes what was the proper time for supper, and he made answer, "If you are a rich man, whenever you please; and if you are a poor man, whenever you can."

Diogenes lighted a candle in the daytime, and went round saying, "I am looking for a man."

When asked what he would take to let a man give him a blow on the head, he said, "A helmet."

Once he saw a youth blushing, and addressed him, "Courage, my boy! that is the complexion of virtue."

When asked what wine he liked to drink, he replied, "That which belongs to another."

Asked from what country he came, he replied, "I am a citizen of the world."

When a man reproached him for going into unclean places, he said, "The sun too penetrates into privies, but is not polluted by them."

Diogenes said once to a person who was showing him a dial, "It is a very useful thing to save a man from being too late for supper."

"Bury me on my face," said Diogenes; and when he was asked why, he replied, "Because in a little while everything will be turned upside down."

Diogenes would frequently praise those who were about to marry, and yet did not marry.

He was once asked what a friend is, and his answer was, "One soul abiding in two bodies."

Asked what he gained from philosophy, he answered, "To do without being commanded what others do from fear of the laws."

The question was once put to him, how we ought to behave to our friends; and the answer he gave was, "As we should wish our friends to behave to us."

He used to define justice as "a virtue of the soul distributing that which each person deserved."

Another of his sayings was, that education was the best viaticum of old age.

The chief good he has defined to be the exercise of virtue in a perfect life.

He used to teach that God is incorporeal, as Plato also asserted, and that his providence extends over all the heavenly bodies.

It was a favourite expression of Theophrastus that time was the most valuable thing that a man could spend.

Antisthenes used to say that envious people were devoured by their own disposition, just as iron is by rust.

When he was praised by some wicked men, he said, "I am sadly afraid that I must have done some wicked thing."

When asked what learning was the most necessary, he said, "Not to unlearn what you have learned."

When Zeno was asked what a friend was, he replied, "Another I."

They say that the first inclination which an animal has is to protect itself.

Nothing can be produced out of nothing.

Xenophanes speaks thus:—And no man knows distinctly anything,And no man ever will.

Democritus says, "But we know nothing really; for truth lies deep down."

Euripides says,—Who knows but that this life is really death,And whether death is not what men call life?

The mountains, too, at a distance appear airy masses and smooth, but seen near at hand, they are rough.

If appearances are deceitful, then they do not deserve any confidence when they assert what appears to them to be true.

The chief good is the suspension of the judgment, which tranquillity of mind follows like its shadow.

Epicurus laid down the doctrine that pleasure was the chief good.

He alludes to the appearance of a face in the orb of the moon.

Fortune is unstable, while our will is free.

Let no one be slow to seek wisdom when he is young nor weary in search thereof when he is grown old. For no age is too early or too late for the health of the soul. And to say that the season for studying philosophy has not yet come, or that it is past and gone, is like saying that the season for happiness is not yet or that it is now no more.

Protagoras asserted that there were two sides to every question, exactly opposite to each other.

It takes a wise man to discover a wise man.

One ought to seek out virtue for its own sake, without being influenced by fear or hope, or by any external influence. Moreover, that in that does happiness consist.

The Stoics also teach that God is unity, and that he is called Mind and Fate and Jupiter, and by many other names besides.

They also say that God is an animal immortal, rational, perfect, and intellectual in his happiness, unsusceptible of any kind of evil, having a foreknowledge of the universe and of all that is in the universe; however, that he has not the figure of a man; and that he is the creator of the universe, and as it were the Father of all things in common, and that a portion of him pervades everything.

But Chrysippus, Posidonius, Zeno, and Boëthus say, that all things are produced by fate. And fate is a connected cause of existing things, or the reason according to which the world is regulated.

Apollodorus says, "If any one were to take away from the books of Chrysippus all the passages which he quotes from other authors, his paper would be left empty."

One of the sophisms of Chrysippus was, "If you have not lost a thing, you have it."

Pythagoras used to say that he had received as a gift from Mercury the perpetual transmigration of his soul, so that it was constantly transmigrating and passing into all sorts of plants or animals.

He calls drunkenness an expression identical with ruin.

Among what he called his precepts were such as these: Do not stir the fire with a sword. Do not sit down on a bushel. Do not devour thy heart.

In the time of Pythagoras that proverbial phrase Ipse dixit was introduced into ordinary life.