Nothing is hidden under the sun.

Wood feeds the fire which burns it.

Where there is shouting, there is no true knowledge.

Those who condemn the supreme certainty of mathematics feed on confusion, and can never silence the contradictions of the sophistical sciences which lead to eternal quackery.

... 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.

One day the world will look upon research upon animals as it now looks upon research on human beings.

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.