Everywhere in nature we seek some certainty, but all this is nothing more than an arrangement of the dark feeling of our own. All the mathematical laws that we find in Nature are always suspicious to me, despite their beauty. They give me no pleasure. They are merely expedients. Everything is not true at close range.

It is very much in the order of nature that toothless animals should have horns: is it any wonder that old men and women should often have them?

Now that we know nature thoroughly, a child can see that in making experiments we are simply paying nature compliments. It is no more than a ceremonial ritual. We know the answers in advance. We consult nature in the same way as great rulers consult their parliaments.

The more experiences and experiments accumulate in the exploration of nature, the more precarious the theories become. But it is not always good to discard them immediately on this account. For every hypothesis which once was sound was useful for thinking of previous phenomena in the proper interrelations and for keeping them in context. We ought to set down contradictory experiences separately, until enough have accumulated to make building a new structure worthwhile.

When they have discovered truth in nature they fling it into a book, where it is in even worse hands.

You can be sure you are acting in accordance with the designs of nature if what you do is calculated to promote nature's great final purpose: grow and make grow. I am firmly convinced of the universality of this law.