Let no man who is not a Mathematician read the elements of my work.

Knowledge is a tangible asset, quite often the most important tool in your work.

Work is external to the worker. . . . It is not part of his nature; consequently he does not fulfill himself in his work but denies himself. . . . The worker therefore feels himself at home only during his leisure time, whereas at work he feels homeless.

To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty, and leave the rest for others that come after you, than to explain all things by conjecture without making sure of anything.

I know that many will call this useless work. Though I may not, like them, be able to quote other authors, I shall rely on that which is much greater and more worthy-on experience, the mistress of their Masters.

Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer. Go some distance away because then the work appears smaller and more of it can be taken in at a glance and a lack of harmony and proportion is more readily seen.