Page:The Harveian oration - delivered at the Royal College of Physicians, London, June 24, 1870 (IA b22307643).pdf/15

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his kind" will be regarded not as the un- eonditioned effect of an absolute will, but as the working out of that will through means laid open to the investigation of science.

To pass from a lower series to a higher, it will be equally admitted that the animal kingdom is sustained at all points by the vegetable kingdom. That the forces exhibited in animal func- tions are those previously stored up in plants by assimilation is a fixed position in phy- siology, and so far the operation of the law of life is plain; but as we pass to a con- sideration of the more intimate modes of it, the difficulties inerease, and yet probably they are not essentially greater difficulties than such as have been overcome by the patienee and docility of those investigators whom it is my duty to eommemorate on this occasion. be objected that there is lurking a kind of petitio principii in the supposed relations of simpler forees to their higher forms; that, for the eonversion of the former into the latter, it is necessary to postulate It may