What is uttered from the heart alone, Will win the hearts of others to your own.

What we agree with leaves us inactive, but contradiction makes us productive.

To make a young couple love each other, it is only necessary to oppose and separate them.

Give me the benefit of your convictions, if you have any; but keep your doubts to yourself, for I have enough of my own.

When you praise someone you call yourself his equal.

Someday someone will write a pathology of experimental physics and bring to light all those swindles which subvert our reason, beguile our judgement and, what is worse, stand in the way of any practical progress. The phenomena must be freed once and for all from their grim torture chamber of empiricism, mechanism, and dogmatism; they must be brought before the jury of man's common sense.

Most men, even the most accomplished, are of limited faculties; every one sets a value on certain qualities in himself and others: these alone he is willing to favour, these alone will he have cultivated.