There must be something unique about man because otherwise, evidently, the ducks would be lecturing about Konrad Lorenz, and the rats would be writing papers about B. F. Skinner.

The most powerful drive in the ascent of man is his pleasure in his own skill. He loves to do what he does well. And having done it well, he loves to do it better.

Revolutions are not made by fate but by men.

It is often said that the progression from simple to complex runs counter to the normal statistics of chance that are formalized in the Second Law of Thermodynamics. Strictly speaking, we could avoid this criticism simply by insisting that the Second Law does not apply to living systems in the environment in which we find them. For the Second Law applies only when there is no overall flow of energy into or out of a system, whereas all living systems are sustained by a net inflow of energy.

In the moment of appreciation we live again the moment when the creator saw and held the hidden likeness.

The child is not a prisoner of its inheritance; it holds its inheritance as a new creation which its future actions will unfold.

Every animal leaves traces of what it was; man alone leaves traces of what he created.