It is this conception of the unity of the human career which is perhaps the greatest achievement of historical study, since it gained a place analogous to that of natural science.
The assumption that nature is all there is, and that nature has been governed by the same rules at all times and places, makes it possible for natural science to be confident that it can explain such things as how life began.
Hence, even in the domain of natural science the aid of the experimental method becomes indispensable whenever the problem set is the analysis of transient and impermanent phenomena, and not merely the observation of persistent and relatively constant objects.
I'm saying that there were many great naturalists before Darwin's time who were very pious people and who knew more about nature than most of us. These were great naturalists; people I would admire for their knowledge of natural science given the time.
The problem with allowing God a role in the history of life is not that science would cease, but rather that scientists would have to acknowledge the existence of something important which is outside the boundaries of natural science.
The theory of relativity worked out by Mr. Einstein, which is in the domain of natural science, I believe can also be applied to the political field. Both democracy and human rights are relative concepts - and not absolute and general.
I hold that the propositions embodied in natural science are not derived by any definite rule from the data of experience, and that they can neither be verified nor falsified by experience according to any definite rule.
But man has still another powerful resource: natural science with its strictly objective methods.
Natural science, does not simply describe and explain nature; it is part of the interplay between nature and ourselves.
Every known fact in natural science was divined by the presentiment of somebody, before it was actually verified.