The old (logical, deductive, so-called "geometric") method is no use in philosophy; but the new one (regressive, analytic) "axiomatic" method is. For it is none other than the "critical" method invented by Kant. Mathematicians such as Hilbert have developed the axiomatic method to such perfection that we should learn from them to come to solid results in philosophy. By following the old mathematical ("dogmatic") method—a method which is perfectly appropriate to mathematics due to the nature of their objects of study—philosophers will fall again and again into the fallacy of concept-swapping.