"I believe that in actual fact philosophy ranks before and above the natural sciences and that all method and exactness serve its intuitions and its intellectual and historical will. In the last analysis it is always a matter of the quod erat demonstrandum. Scientific freedom from assumptions is or should be a moral fact. But intellectually it is, as Freud points out, probably an illusion. One might strain the point and say that science has never made a discovery without being authorized and encouraged by philosophy."