mission--his only object is to confound the principle which he has accepted by means of the reaction of its consequence. The inevitable consequence which ensues when the analysis of the perception of matter is admitted is the extinction of all belief in the existence of matter. The analysis gives us a kind of matter to believe in to which no belief corresponds. The sceptic is content with pronouncing this to be the fact without going into its reason. It is not his business to correct, by a direct exposure, the error of the principle which the dogmatist lays down, and which he accepts. The analysis is the psychologist's affair; let _him_ look to it. Were the sceptic to make it his, he would emerge, from the sceptical crisis, and pass into a new stage of speculation. He, indeed, subverts it indirectly by a _reductio ad absurdum_. But he does not _say_ that he subverts it--he leaves the orthodox proposer of the principle to find that out. Reid totally misconceived the nature of scepticism and idealism in their bearings on this problem. He regarded them as habits of thought--as dispositions of mind peculiar to certain individuals of vexatious character and unsound principles, instead of viewing them as catholic eras in the development of all genuine speculative thinking. In his eyes they were subjective crotchets limited to some, and not objective crises common to all, who think. He made _personal_ matters of them--a thing not to be endured. For instance, in dealing with Hume, he conceived that the scepticism which confronted him in the pages of that great genius, was _Hume's_ scepticism, and was not the scepticism of human nature at large,--was not his own scepticism just as much as it was Hume's. _His_ soul, so he thought, was free from the obnoxious flaw, merely because _his_ anatomy, shallower than Hume's, refused to lay it bare. With such views it was impossible for Reid to eliminate scepticism and idealism from philosophy. These foes are the foes of each man's own house and heart, and nothing can be made of them if we attack them in the person of another. Ultimately and fairly to get rid of them, a man must first of all thoroughly digest them, and take them up into the vital circulation of his own reason. The only way of putting them back is by carrying them forward.