6
HARVEY AND GALEN
law of continuous evolution. We imagine that such men as Aristotle, Galileo* Harvey, and Newton were indepen- dent of their predecessors, that, in fact, their great work was to demolish the errors — that is, to destroy the work — of those predecessors and to start afresh. But in reality no man, even the greatest, was ever thus independent. The investigator is indebted to those who went before him, not only for the instruments of research which they per- fected, but for the conclusions which they arrived at. These conclusions* whether he admits or rejects them, serve for his help and guidance. It is easy to see how a discoverer profits by the ascertained discoveries of his forerunners. It is not so easily seen that the so-called errors of those men are also of great value to him. How many false solutions of a problem are required before the true solution is arrived at ! HoW many are, indeed, neces- sary elements in this final solution ! I know that there are various kinds of errors, and that* while some are stepping-stones, others are stumbling-blocks ; but still there is much truth in the general proposition that error is a stage in the development of truth. A certain novelist has sketched the character of a philosopher who devoted his life to writing the History of Human Error. Were such a work ever honestly written it would be the History of Human Progress. I ask your indulgence for entering on these abstract topics, because they will be found to bear immediately upon my subject, which is The Relation of Harvey to his Predecessors , and especially to Galen.
It will be found, I think, that after tracing the services of Harvey’s own generation and that immediately preceding it in providing him with the indispensable methods and instruments of research we are led back to Aristotle and Galen as the real predecessors of Harvey in his work concerning the heart. It was by the labours of the great school of Greek anatomists, of whom Galen was the final representative (not forgetting their successors in the six- teenth century), that the problem, though unsolved, was put in such a shape that the genius of Harvey was enabled
