I am exclusively occupied with the problem of gravitation and hope with the help of a local mathematician friend [Marcel Grossman] to overcome all the difficulties. One thing is certain, however, that never in life have I been quite so tormented. A great respect for mathematics has been instilled within me, the subtler aspects of which, in my stupidity, I regarded until now as pure luxury.
One of the biggest lessons I've learned recently is that when you don't know what to do, you should do nothing until you figure out what to do because a lot of times you feel like you are pressed against the wall, and you've got to make a decision. You never have to do anything. Don't know what to do? Do nothing.
I hear therefore with joy whatever is beginning to be said of the dignity and necessity of labor to every citizen. There is virtue yet in the hoe and the spade, for learned as well as for unlearned hands. And labor is everywhere welcome; always we are invited to work; only be this limitation observed, that a man shall not for the sake of wider activity sacrifice any opinion to the popular judgments and modes of action.
Trace Science, then, with Modesty thy guide,
First strip off all her equipage of Pride,
Deduct what is but Vanity or Dress,
Or Learning's Luxury or idleness,
Or tricks, to show the stretch of the human brain
Mere curious pleasure or ingenious pain.
A young man is not a proper hearer of lectures on political science; for he is inexperienced in the actions that occur in life, but its discussions start from these and are about these; and, further, since he tends to follow his passions, his study will be vain and unprofitable, because the end that is aimed at is not knowledge but action. And it makes no difference whether he is young in years or youthful in character.