The Kantian method is of course but one of anumber of the philosophic attempts at harmonization. There is one phase of it which may be said to continue the Cartesian attempt to find the locus of absolute certainty within the knowing mind itself, surrendering both the endeavor of the ancients to dis- cover it in the world without, and of the medieval world to find it in an external revelation. In his search for forms and categories inherent in the very structure of knowing activity, Kant penetrated far below the superficial level of innate ideas in which his predecessors had tried to find the locus of certainty. Some of them were conditions of the possibility of there being such athing as cognitive experience.