There were many others belonging to this school besides Reid and Stewart, whom it would be impossible to speak of here. The Scottish Philosophy had its work to do, and no doubt understood that work--the first essential in a criticism: it endeavoured to vindicate perception as against sensational idealism, and it only partially succeeded in its task. But we must be careful not to forget that it opened up the way for a more comprehensive and satisfactory point of view. It was with Kant that the distinction arose between sensation and the forms necessary to its perception, the form of space and time, and so on. As to this part of the theory of knowledge, Reid and his school were not clear; they only made an effort to express the fact that something was required to verify our knowledge, but they were far from satisfactorily attaining to their goal. The very name of 'common-sense' was misleading--making people imagine, as it did, that there was nothing in philosophy after all that the man in the street could not know by applying the smallest modicum of reflection to the subject. Philosophy thus came to be considered as superfluous, and it was thought that the sooner we got rid of it and were content to observe the mandates of our hearts, the better for all concerned. What, then, was the work which Ferrier placed before himself when he commenced to write upon and teach philosophy? He was thoroughly and entirely dissatisfied with the old point of view, the point of view of the 'common-sense' school of metaphysicians, to begin with. Sometimes it seems as though we could not judge a system altogether from the best exponent of it, although theoretically we are always bound to turn to him. In a national philosophy, at least, we want something that will wear, that will bear to be put in ordinary language, something which can be understood of the people, which can be assimilated with the popular religion and politics--in fact, which can really be _lived_ as well as thought; and it is only after many years of use that we can really tell whether these conditions have been fulfilled. For this reason we are in some measure justified in taking the popular estimate of a system, and in considering its practical results as well as the value of its theory. Now, the commonly accepted view of the eighteenth-century philosophers in Scotland is that there is nothing very wonderful about the subject--like the _Bourgeois Gentilhomme_ of Molière, we are shown that we have been philosophising all our lives, only we never knew it. 'Common-sense'--an attribute with which we all believe we are in some small measure endowed--explains everything if we simply exercise it, and that is open to us all: there has been much talk, it would seem, about nothing; secrets hidden to wise men are revealed to babes, and we have but to keep our minds open in order to receive them.