Perspective is a most subtle discovery in mathematical studies, for by means of lines it causes to appear distant that which is near, and large that which is small.

Ask advice of him who governs himself well.

Wisdom is the daughter of experience

Wherever good fortune enters, envy lays siege to the place and attacks it; and when it departs, sorrow and repentance remain behind.

Avoid studies of which the result dies with the worker.

He who does not understand the supreme certainty of mathematics is wallowing in confusion.

Fix your course on a star and you'll navigate any storm.