 Postpositivism's poster became Popper's view of human knowledge as hypothetical, continually growing, always tentative, open to criticism and revision.But then even Popper became unpopular, allegedly unreslistic.In 1945, Bertrand Russell had proposed enumerative induction as an "independent logical principle", one "incapable of being inferred either from experience or from other logical principles, and that without this principle, science is impossible".