Those who are in love with practice without knowledge are like the sailor who gets into a ship without rudder or compass and who never can be certain whether he is going. Practice must always be founded on sound theory, and to this Perspective is the guide and the gateway; and without this nothing can be done well in the matter of drawing.

To lie is vile, to tell truth is excellent, if not noble.

To be a winner you must want to win but must know of the chance of losing and must not fear of it.

Oh! Speculators on things, boast not of knowing the things that nature ordinarily brings about; but rejoice if you know the end of those things which you yourself device.

If you are alone you belong entirely to yourself. If you are accompanied by even one companion you belong only half to yourself or even less in proportion to the thoughtlessness of his conduct and if you have more than one companion you will fall more deeply into the same plight.

It is the infinite alone that cannot be attained, for if it could it would become finite.

An arch consists of two weaknesses which, leaning one against the other, make a strength.