Aristotle

Teleology is the study of final causes in nature.

The study of animals is the beginning of philosophy.

Nothing happens in nature without a reason.

The more perfect animals are those in which the body is complex.

As the hand is to the body, so the mind is to the soul.

The unexamined life is not worth living.

Happiness is the meaning and the purpose of life, the whole aim and end of human existence.

The greatest virtues are those which are most useful to other persons.

A friend to all is a friend to none.

Poverty is the parent of revolution and crime.

The aim of art is to represent not the outward appearance of things, but their inward significance.

Hope is a waking dream.

Moral excellence comes about as a result of habit. We become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts.

The soul never thinks without a mental image.

To avoid criticism, say nothing, do nothing, be nothing.

The best way to predict the future is to create it.

The whole is greater than the sum of its parts.

Personal beauty is a greater recommendation than any letter of reference.

Dignity consists not in possessing honors, but in deserving them.

The wise man does not expose himself to danger unnecessarily, since there are few things for which he cares sufficiently; but he is willing, in great crises, to give even his life — knowing that under certain conditions it is not worthwhile to live.