Insofar as he makes use of his healthy senses, man himself is the best and most exact scientific instrument possible. The greatest misfortune of modern physics is that its experiments have been set apart from man, as it were, physics refuses to recognize nature in anything not shown by artificial instruments, and even uses this as a measure of its accomplishments.

I curse all negative purism that tells me not to use a word from another language that either expresses something that my own language cannot or does that in a more delicate manner.

When young, one is confident to be able to build palaces for mankind, but when the time comes one has one's hands full just to be able to remove their trash.

Nothing can be compared to the new life that the discovery of another country provides for a thoughtful person. Although I am still the same I believe to have changed to the bones.

Keep not standing fixed and rooted. Briskly venture, briskly roam.

Whoever makes it a rule to test action by thought, thought by action, cannot falter, and if he does, will soon find his way back to the right road.

If one doesn't know one's own country, one doesn't have standards for foreign countries.