Those that know, do. Those that understand, teach – Aristotle

Jealousy is both reasonable and belongs to reasonable men, while envy is base and belongs to the base, for the one makes himself get good things by jealousy, while the other does not allow his neighbour to have them through envy – Aristotle

There was never a genius without a tincture of madness – Aristotle

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

Courage is the first of human qualities because it is the quality which guarantees the others – Aristotle

Misfortune shows those who are not really friends – Aristotle