"Science, as the positivist understands it, is susceptible of infinite progress. That you learn in every elementary school today, I believe. Every result of science is provisional and subject to future revision, and this will never change. In other words, fifty thousand years from now there will still be results entirely different from those now, but still subject to revision. Science is susceptible of infinite progress. But how can science be susceptible of infinite progress if its object does not have an inner infinity? The belief admitted by all believers in science today — that science is by its nature essentially progressive, and eternally progressive — implies, without saying it, that being is mysterious. And here is the point where the two lines I have tried to trace do not meet exactly, but where they come within hailing distance. And, I believe, to expect more in a general way, of people in general, would be unreasonable."