From having never properly secreted scepticism and idealism in his own mind, Reid fell into the commission of one of the gravest errors of which a philosopher can be guilty. He falsified the fact in regard to our primitive beliefs--a thing which the obnoxious systems against which he was fighting never did. He conceived that scepticism and idealism called in question a fact which was countenanced by a natural belief; accordingly, he confronted their denial with the allegation that the disputed fact--the existence of matter _per se_--was guaranteed by a primitive conviction of our nature. But this fact receives no support from any such source. There is no belief in the whole repository of the mind which can be fitted on to the existence of matter denuded of all perception. Therefore, in maintaining the contrary, Reid falsified the fact in regard to our primitive convictions--in regard to those principles of common sense which he professed to follow as his guide. This was a serious slip. The rash step which he here took plunged him into a much deeper error than that of the sceptic or idealist. They err[24] in common with him in accepting as their starting-point the analysis of the perception of matter. He errs, by himself, in maintaining that there is a belief where no belief exists. But do not scepticism and idealism doubt matter's existence _altogether_, or deny to it _any_ kind of existence? Certainly they do; and in harmony with the principle from which they start they must do this. The _only_ kind of matter which the analysis of the perception of matter yields, is matter _per se_. The existence of such matter is, as we have shown, altogether uncountenanced either by consciousness or belief. But there is no other kind of matter in the field. We must therefore either believe in the existence of matter _per se_, or we must believe in the existence of _no_ matter whatever. We do not, and we cannot believe in the existence of matter _per se_; therefore, we cannot believe in the existence of matter at all. This is not satisfactory, but it is closely consequential.