In her enduring study of the impact of Darwinism on the intellectual climate of the nineteenth century, Gertrude Himmelfarb brings massive documentation to bear in challenging the conventional view of Darwin's greatness. Touching on biography, history, and philosophy, she traces the origins and development of Darwin's views against the opinions of his time; assesses the influences on him; and shows what he intended his theory to mean, what his readers took it to mean, And what it has in fact meant. By such a route Ms. Himmelfarb recaptures "a sense of how a scientist, with the most innocent of intentions and the best of faith, can give birth to a theory that has an ancestry and a posterity of which he may be ignorant and a life of its own over which he has no control."