Aristotle

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

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.

A friend is one soul abiding in two bodies.

Hope is the dream of a waking man.

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.

Nature does not do anything in vain.

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.

Misfortune shows those who are not really friends.

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.

In every systematic inquiry where there are first principles, or causes, or elements, knowledge and science result from acquiring knowledge of these.

It is solved by walking.

All men by nature desire to know.

We are what we repeatedly do. Excellence, then, is not an act, but a habit.

Knowing yourself is the beginning of all wisdom.