"Science never pursues the illusory aim of making its answers final, or even probable. Its advance is, rather, towards an infinite yet attainable aim: that of ever discovering new, deeper, and more general problems, and of subjecting our ever tentative answers to ever renewed and ever more rigorous tests."
—Karl Popper, The Logic of Scientific Discovery (1959)
"There is no better synonym for “rational” than “critical”. (Belief, of course, is never rational: it is rational to suspend belief.)
—Karl Popper, Unended Quest.