The contention of the above comment, as I understand it, is that there is, analogously to the problem of trisecting an arbitrary angle in mathematics, a sound demonstration, along the lines employed by Hume and Russell, of skeptical conclusions concerning our inductive knowledge of the future, and that hence one is mistaken in imputing to that argument, as I have done, a logical slip arising from a confusion in the use of ‘future’ and other similar words. I am indebted to Mr. Wang for the stimulation, and to the Editor of Philosophy of Science for the opportunity, to try to make my points clearer.

The proponents of these skeptical arguments maintain that, apart from some supporting postulates which we must make in inductions about the future, we have no evidence concerning the future of any given moment. If we restrict ourselves to the evidence we have from the present and the past, and do not bolster this evidence with some Principle of Induction, like that of Hume to the effect that the future will be like the past, “we have no theoretical assurance,” as Mr. Wang puts it, “that the practice of guiding our activities by what we learn from ... [the past] will lead to success on the whole and in the long run.”