Aristotle, the ancient Greek philosopher and scientist, was one of the two greatest intellectual figures produced by the Greeks (the other being Plato). He surveyed the whole of human knowledge as it was known in the Mediterranean world in his day. Aristotle's intellectual range was vast, covering most of the sciences and many of the arts. He worked in physics, chemistry, biology, zoology, and botany; in psychology, political theory, and ethics; in logic and metaphysics; in history, literary theory, and rhetoric.
His greatest achievements were in two unrelated areas: he invented the study of formal logic, devising for it a finished system, known as Aristotelian syllogistic, that for centuries was regarded as the sum of logic; and he pioneered the study of zoology, both observational and theoretical, in which his work was not surpassed until the 19th century. Aristotle's historical importance is second to none, and his work remains a powerful component in current philosophical debate.
We are what we repeatedly do. Excellence, therefore, is not an act but a habit.
A man who is angry on the right grounds, against the right persons, in the right manner, at the right moment, and for the right length of time deserves great praise.
All human actions have one or more of these seven causes: chance, nature, compulsions, habit, reason, passion, desire.
Dignity consists not in possessing honors, but in the consciousness that we deserve them.
Happiness is the meaning and the purpose of life, the whole aim and end of human existence.
If things do not turn out as we wish, we should wish for them as they turn out.
It is the mark of an educated mind to be able to entertain a thought without accepting it.
My best friend is the man who in wishing me well wishes it for my sake.
The worst form of inequality is to try to make unequal things equal.
What is a friend? A single soul dwelling in two bodies.