certainty as that with which astronomy asserts that the earth moves round the sun; for a conclusion may be arrived at as safely by other methods as by mathematical calculation.
"If I make this assertion so unhesitatingly I do not make it in the belief that I am bringing forward anything new, nor because I think that any opposition will be encountered, but simply because I wish to begin by pointing out the firm ground on which we stand, before considering the numerous problems which still remain unsolved.
"Such problems appear as soon as we pass from the facts of the case to their explanation; as soon as we pass from the statement, The organic world has arisen by development, to the question, But how has this been effected, by the action of what forces, by what means, and under what circumstances?
"In attempting to answer these questions we are very far from dealing with certainties; and opinions are still conflicting. But the answer lies in the domain of future investigation, that unknown country which we have to explore.
"It is true that this country is not entirely unknown, and if I am not mistaken, Charles Darwin, who in our time has been the first to revive the long dormant theory of descent, has already given a sketch, which may well serve as a basis for the complete map of the domain; although perhaps many details will be added, and many others taken away. In the principle of natural selection, Darwin has indicated the route by which we must enter this unknown land."—Weismann.
"The continuity of the germ plasm, like Darwin's selection, is a fact not a theory."—Haycraft.
"'Struggle for existence,' as perhaps it was in Mr. Darwin's world of advancing beasts and developing vegetables. But now the plan is so turned about by the arrival of man on the scene, and by his civilization, that you cannot watch even Darwin and Huxley themselves without seeing that the struggle that they and other good men wage is no struggle for existence but a struggle against mere existence. The struggle for existence is brutal life; a struggle to do something more than exist is human life—the mission of the human soul. What is the use of alcohol in such a struggle? The question is a wide one. It might lead us to inquire what that is which men want to obtain beyond mere existence. Watching some eminent teachers, you might suppose it to be a very detailed knowledge of the common frog.