question as to the possibility of those synthetic propositions a priori is not answered. It is not even seriously asked. We are just told that they are "evident "and that, therefore, their validity cannot be doubted. Well — Kant maintained that his synthetic judgments a priori were evidently beyond all doubt, but that was just what puzzled him and made it necessary for him to write the whole Critique of Pure Reason. Kant's arguments have no validity for the phaenomenologist, for, even if they were correct, they could account for a formal a priori only. Thus the material synthetic a priori judgments remain entirely unjustified, Husserl makes no attempt to explain the incredible "fact" that synthetic knowledge can be valid a priori. Certainly we should entertain serious suspicions as to the existence of this "fact". Are the phaenomenologists right in assuming that the above mentioned propositions (or similar ones) express real synthetic knowledge ?
If this were the case it could form a second reason for great astonishment. If it is a synthetic proposition, a relevant truth, that e. g. every colour must have some extension, why does it appear to us as a simple truism? why is it our first impulse to say; "why, yes, naturally" what of it ? why don't we feel inclined to exclaim "ah, how interesting! this matter deserves to be investigated!" as we should when confronted with Euclid's fifth postulate or with the principle of causality? Real synthetic propositions always give rise to a sequence of new discoveries, because they must have some foundation which we are anxious to find (that is, since in reality all "synthetic propositions are empirical statements of fact, we simply inquire into the causes or laws of that fact) ; but the great truths of "phaenomenology" appear to be final, incapable of explanation, and therefore — in spite of Husserl's assertions to the contrary — do not form the base of any progressive science. This is another reason why we feel convinced that those propositions cannot possibly have the character of a "material a priori".
After what has been said before it is easy for us to discover the fundamental error of this philosophy (I have just been criticising). It is, of course, perfectly true, that there is no colour without an extension, that every tone must have a pitch, that orange necessarily ranges between yellow and red, that the same place in our visual field cannot be both red and green at the same time and so on. These truths are certainly a priori, no possible experience can contradict them — what is there about them that made
