GEORGE STUABT FULLERTON, A System of Metaphysics. 235 though it is such in relation to the stream of consciousness, it has its inalienable place in the physical system, in the standard content. The fact that " order " is found in our experiences is what makes life possible ; the more of it we find, the better in general for life. Hence we give the more regard to those elements of experience which lend themselves better to treatment as an order. When, within the general order of physical experiences, " we distinguish a nucleus which is peculiarly serviceable in definitely ordering and arranging the whole, certain of our sensations take the place of signs and others come to hold the more dignified position of thing signified ". Here we have the distinction between appearance and reality. But the application to any given complex of sensations of the term "appearance" does not in the least do away with the reality to which it may lay claim in that it is a complex of sensa- tions. If it did not belong to one system with the thing signified, it could not serve as a sign. The word " system " is here used in a more inclusive sense. When the scientific thinker concentrates attention upon the mass and energy of matter in motion and calls most of its apparent qualities merely "subjective," "he is separ- ating from the mass of his sensational experiences a certain group which can be made to fall into a definite and measurable system, and which can serve as a means for relating and ordering sensa- tions of every kind ". Atoms, molecules and their laws are a working hypothetic completion of that apparent system in physi- cal experiences which is what constitutes their objectivity. So far as the hypothesis fits our widening and elaborated experience, we are encouraged to think that a sufficiently complete experience would realise its terms. " We are dealing with a construct, and objects are called real when it seems reasonable to assign them a place in that construct." Despite much affinity in this account to those of Berkeley, Mill and others, there are noteworthy differences. It is recognised that a thing, though wholly phenomenal, is not identical with the psychological fact called a percept and therefore does not cease to exist, or begin to be "potential," when the psychological fact ceases. Prof. Fullerton affords materials for a complete reply to objection here, though he does not put them in the form of such a reply. If, for instance, it were urged that, when we turn away, the table, having no basis of existence but experience, is not there any longer, the answer would be that if there is a " there," there is a table ; the space in question having the same basis of existence as the thing in question. So much is obvious ; but, if the objector, amending his language, now says, " At least it is true on your principles that, when the percept does not exist, the object (and its space as well) do not exist," the answer is, that if there is a " when, ' there is a table ; the time in question having the same basis of existence as the object. Out of psychological space and psychological time are produced the " constructs " of