So many times have we heard it told and even recounted it ourselves, that the tale of Descartes’ metaphysical adventure is something we can slip our philosophical feet into without feeling the slightest pinch. The story, or perhaps, only its plot, is this: Descartes, in order to discover whether anything is certain, attempted to doubt everything; though he succeeded in casting at least a shadow of doubt on vast areas of belief, happily one item, though only one, emerged from the inquiry in a respectable condition, indubitable. The remainder of the tale relates how he proceeded to deduce truth after truth from that single original certainty.