There is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance.
There could be no fairer destiny for any physical theory than that it should point the way to a more comprehensive theory in which it lives on as a limiting case.
Anyone who proposes to do good must not expect people to roll stones out of his way, but must accept his lot calmly, even if they roll a few stones upon it.
What with making their way and enjoying what they have won, heroes have no time to think. But the sons of heroes ah, they have all the necessary leisure.
It is a bit embarrassing to have been concerned with the human problem all one's life and find at the end that one has no more to offer by way of advice than 'try to be a little kinder.'
Safety from external danger is the most powerful director of national conduct. Even the ardent love of liberty will, after a time, give way to its dictates.