Although nature commences with reason and ends in experience it is necessary for us to do the opposite, that is to commence with experience and from this to proceed to investigate the reason.

A man was desired to rise from bed because the sun was already up. He replied: "If I had as far to go and as much to do as he has, I should be up by now; but having but a little way to go, I shall not get up yet."

While you are alone you are entirely your own master and if you have one companion you are but half your own, and the less so in proportion to the indiscretion of his behavior.

It is easier to contend with evil at the first than at the last.

The young man should first learn perspective, then the proportions of objects. Next, copy work after the hand of a good master, to gain the habit of drawing parts of the body well; and then to work from nature, to confirm the lessons learned.

Inequality is the cause of all local movements.

All our knowledge is the offspring of our perceptions.