What I really need is to get clear out about what I must do, not what I must know, except insofar as knowledge precedes every act.
The true method of knowledge is experiment.
As our circle of knowledge expands, so does the circumference of darkness surrounding it.
One sees great things from the valley; only small things from the peak.
If we do not plant knowledge when young, it will give us no shade when we are old.
Luck is not something you can mention in the presence of self-made men.
The great thing in the world is not so much where we stand, as in what direction we are moving.
The pleasures of ignorance are as great, in their way, as the pleasures of knowledge.
It's not stress that kills us, it is our reaction to it.
Character may almost be called the most effective means of persuasion.