Pursuing the approach of M. Gueroult, the author shows that Descartes conceived of the function of philosophy as being strictly transcendental (ante litteram). The analytic method which he demanded (contrary to the geometric method) had to be a deductive method in terms of Euclid. Lauth shows how Descartes as the originator of scientific-systematic philosophizing took his place beside Kant, Reinhold, Fichte and the modern transcendental philosophers. With regard to Bacon, Spinoza, Leibniz, Kant, Hegel and Fichte, the author shows clearly the extent to which Descartes developed and also implemented the concept of his system in his main works (Regulae, Discours, Meditationes, Recherche de la Vérité).