Nature is constrained by the cause of her laws which dwell inborn in her. Variant: Nature is constrained by the order of her own law which lives and works within her.

In rivers, the water that you touch is the last of what has passed and the first of that which comes; so with present time.

I love those who can smile in trouble, who can gather strength from distress, and grow brave by reflection. 'Tis the business of little minds to shrink, but they whose heart is firm, and whose conscience approves their conduct, will pursue their principles unto death.

Life well spent is long.

Those who are enamoured of practice without science are like a pilot who goes into a ship without rudder or compass and never has any certainty of where he is going. Practice should always be based upon a sound knowledge of theory.

The poet ranks far below the painter in the representation of visible things, and far below the musician in that of invisible things.

When you draw a nude, sketch the whole figure and nicely fit the members to it and to each other. Even though you may only finish one portion of the drawing, just make certain that all the parts hang together, so that the study will be useful to you in the future.