=The Method of Descartes.= Both science and scholasticism show themselves in the method of Descartes. He attempted to construct a philosophical method entirely in the scientific spirit of the Renaissance, but in the application of it he showed his scholastic training. Surfeited with inadequate and traditional methods he felt the need of some single principle by which all knowledge might be systematized, and he was sure that mathematics would furnish the key. Rational science was to Descartes only mathematics. Truth is to be found not in metaphysics, nor in empirical science. Descartes’ philosophical aim was to establish a universal mathematics. Descartes was not entirely faithful to Galileo’s mathematical principle in his employment of it, and his influence in metaphysics was thereby all the greater; for in the development of his method he found assistance in the traditional scholastic methods. Descartes was original in insisting upon finding the existence of an absolute and undeniable principle before any progress could be made. Such an absolute principle can be obtained only by an _inductive sifting of all ideas_. From this all further truths must be obtained by _deduction_. Every true philosophy must therefore be an induction or analysis of ideas, and secondly, a deduction or synthesis. _The great contribution of Descartes was therefore this: to the inductive method of Bacon and the deductive method of Galileo, he added an absolute principle which must be taken as the basis of both induction and deduction._[27]