Quote: Dobzhansky on the hope of human knowledge

Theodosius Dobzhansky, “Man and Natural Selection” (American Scientist 49:285, 1961):

By changing what man knows about the world, he changes the world he knows; and by changing the world in which he lives, he changes himself. Herein lies a danger and a hope; a danger because random changes of the biological nature are likely to produce deterioration rather than improvement; a hope because changes resulting from knowledge can also be directed by knowledge.