It is entirely otherwise with the problem how far does the regress ex tend when it ascends from the given conditioned to its conditions in the series: whether I can say here that there is a regress to infinity or only a regress extending indetenninately far (in indefinitum), and whether from human beings now living I can ascend to infinity in the series of their ancestors, or whether it can be said only that as far as I have gone back, there has never been an empirical ground for holding the series to be bounded anywhere, so that for every forefather I am justified in seek ing, and at the same time bound to seek, still further for his ancestors, though not to presuppose them?