The further one advances in experience, the closer one comes to the unfathomable; the more one learns to utilize experience, the more one recognizes that the unfathomable is of no practical value.

Shakespeare is dangerous to young poets; they cannot but reproduce him, while they fancy that they produce themselves.

There is nothing so terrible as activity without insight.

Every solution of a problem is a new problem.

It is equally a mistake to hold one's self too high, or to rate one's self too cheap.

What one doesn't understand one doesn't possess.

To understand one thing well is better than understanding many things by halves.