To have striven, to have made the effort, to have been true to certain ideals - this alone is worth the struggle.
The teacher's life should have three periods, study until twenty-five, investigation until forty, profession until sixty, at which age I would have him retired on a double allowance.
No human being is constituted to know the truth, the whole truth, and nothing but the truth; and even the best of men must be content with fragments, with partial glimpses, never the full fruition.
Shut out all of your past except that which will help you weather your tomorrows.
The future is today.
The value of experience is not in seeing much, but in seeing wisely.