Peter Medawar

The enthusiasm of a scientist's mind is as great as the secrecy of it ever was.

Biology is founded on the principle of individuality.

Old age is like a second childhood, only with all the drawbacks and none of the charm.

I can say with perfect truth that I have never in my life been bored.

The human mind delights in finding pattern and inventing principles and causes.

Science is an imaginative adventure of the mind seeking truth in a world of mystery.

To be master of any branch of knowledge, one must first master oneself.

The greatest satisfaction in scientific work is the discovery of truth.

In science, as in love, a concentration on the process can blind one to the end.

Aging is an inevitable process, but it need not be a defeat.

The pursuit of science is a noble one, fraught with passion and peril.

Criticism is the lifeblood of science.

Nature does not know distinction between good and evil; that is a human invention.

The scientist's life should be governed by a code of honor.

Imagination is the true beginning of all creation.

In biology, the whole is greater than the sum of its parts, but only just.

To understand life is to understand its limits.

Humor is the great lubricant of intellectual discourse.

The immune system is the body's army, ever vigilant.

Philosophy without science is empty; science without philosophy is blind.