If a conclusion is not poetically balanced, it cannot be scientifically true.

Boasts are wind and deeds are hard.

Politically popular speech has always been protected: even the Jews were free to say ‘Heil Hitler.’

But life is glorious when it is happy; days are carefree when they are happy; the interplay of thought and imagination is far and superior to that of muscle and sinew. Let me tell you, if you don't know it from your own experience, that reading a good book, losing yourself in the interest of words and thoughts, is for some people (me, for instance) an incredible intensity of happiness.

To test a perfect theory with imperfect instruments did not impress the Greek philosophers as a valid way to gain knowledge.

I made up my mind long ago to follow one cardinal rule in all my writing — to be clear.

Tell me why the stars do shine, Tell me why the ivy twines, Tell me what makes skies so blue, And I'll tell you why I love you. Nuclear fusion makes stars to shine, Tropisms make the ivy twine, Raleigh scattering make skies so blue, Testicular hormones are why I love you.