Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.

To speak well of a base man is much the same as speaking ill of a good man.

Experiment is the sole interpreter of the artifices of Nature.

Old age takes in part savoury wisdom for its food - see to that your old age will not lack in nourishment.

It's not enough that you believe what you see. You must also understand what you see.

... we might say that the earth has a spirit of growth; that its flesh is the soil, its bones the arrangement and connection of the rocks of which the mountains are composed, its cartilage the tufa, and its blood the springs of water.

Anyone who invokes authors in discussion is not using his intelligence but his memory.