494 W. R. BOYCE GIBSON : the object of its thought the world -under one general concept. Avenarius points out at some length that these two characteristics of apperception are both essentially econo- mical processes, 1 and as they are, taken together, peculiarly the processes proper to philosophic thinking, Philosophy has its roots in the principle of economy. The main objection I would make to the reasoning of Avenarius is that it does not appear to me to be founded on a true psychological analysis. Avenarius proves fully, and often most ingeniously, that an element of economy is to be found in all the various specific processes he treats of, but he does not prove what he avowedly aims at proving that conation in its theoretical aspect as apperception is a striving to think economically. The element of economy that he invariably discovers is not shown to be the element that dominates the striving, and this, in my opinion, renders the whole argument artificial and misleading. As a typical instance of the method of Avenarius, let me take the following. After pointing out with true psycho- logical insight that in systematic thought we have (1) the domination and continuous application of a central idea ; (2) a perpetual strengthening of the meaning of the inter- connected ideas through their connexions with one another and the central idea ; (3) a facilitation in applying the idea brought about through constantly applying it, he adds : ' These are, collectively, effort-saving considerations '. 2 They undoubtedly are, but they are also the considerations for effective, i.e., successful work, and success to the striver is of much more importance than economy. Avenarius cheats us throughout by presenting us with an abstract universal, a uniformly present common element, in the place of the con- cretely determined universal. Economy per se is a mere formal principle, and as such incapable of determining its own limits. Let us take the case of Descartes' treatise on Geometry. Its conciseness is such that even Newton found it hard to master. Descartes confided to a friend that he had purposely abbreviated the solutions in order that critics might not say to him, ' Well, any one could have discovered that'. Here we have the most rigid economy, from the quantitative point of view, the maximum number of solu- tions with the minimum outlay of means. But this is not 1 Avenarius, id., p. 10 : ' The impulse to apperoeive is nothing else than the endeavour of the mind to economise its force '. 2 Avenarius, id., p. 6.