The proper and useful habit of designating that which is permanent by a _single_ name, and of comprehending the same in a _single_ thought, without analysing at each operation its constituent parts, is liable to come into singular conflict with the tendency to separate these constituent parts. The obscure image formed of the permanent, which does not perceptibly change when one or another constituent part is taken away, appears to be something existent _by itself_. Inasmuch as it is possible to take away _singly_ every constituent part without effecting the capacity of the image formed to _represent_ the totality involved, or effecting its subsequent recognition, it is imagined that it is possible to take away _all_ these parts and yet have something remaining. Thus arises the monstrous idea of a _thing of itself_, different from, and incognisable with relation to, its "phenomenal" existence.
Thing, body, matter, are nothing apart from this complex of colors, sounds, and so forth—apart from their so-called marks, or characteristics. That Protean, illusory philosophical problem of a _single_ independent thing with _many_ properties, arises from the misunderstanding of the fact, that extensive comprehension and accurate separation, although both are temporarily justifiable and profitable for a number of purposes, can not and must not be employed _simultaneously_. A body is _single_ and unchangeable so long as it is not required to take details into consideration. Thus both the earth and a billiard ball are _spheres_ so long as we disregard all minor deviations from the spherical form, and greater exactitude is not necessary. But if we are compelled to carry on investigations in orography or microscopy both bodies cease to be spheres.
Man possesses in pre-eminence the power to determine arbitrarily and consciously his point of view. He can at one time disregard the most salient features, and immediately afterwards take into account the smallest trifles; now regard a current of electricity as fixed, without consideration of its contents, and now determine the width of a Frauenhofer line in the solar spectrum; he can rise, at will, to the most general abstractions, or bury himself in the minutest particulars. The animal possesses this capacity in a much less degree. It does not assume a point of view, but usually is brought to it by impressions. The baby that does not recognise its father with his hat on, the dog that is perplexed at the new coat of its master, have succumbed in the conflict of points of view. Who has not been thus worsted in similar cases? Even the man of philosophy at times succumbs, as the fantastic problem above referred to, shows.