Philosophical systems are never definitively proved false!

"Philosophical systems are never definitively proved false; they are simply discarded or put aside for future use. And this means that the history of philosophy consists not simply of dead museum pieces but of ever-living classics – comprising a permanent repository of ideas, doctrines, and arguments and a continuing source of philosophical inspiration and suggestiveness to those who philosophize in any succeeding age. It is for this reason that any attempt to separate philosophizing from the history of philosophy is both a provincial act and an unnecessary impoverishment of its rich natural resources."