Ask counsel of him who rules himself well.
Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.
It's easier to resist at the beginning than at the end.
Inaction saps the vigor of the mind.
The eye - which sees all objects reversed - retains the images for some time.
Knowledge ... shall always bear witness like a clarion to its creator.