objects, therefore, are the smallest number requisite to constitute consciousness. On the other hand, objects are conceived as identical by an attention to their points of agreement; though conception may also be regarded as perception applied to a group of objects, so as to bring before the mind its class characteristics; the word well expressing the gathering into one of the several qualities or properties by which the group is distinguished from other groups. Conception is, therefore, the source of ideas, and the word concept expresses the union effected in the mind of those attributes or properties under which a given object is at any moment recognized. In other words, it is "the complement of properties characteristic of a particular class." If the class be a very special one the concept will apply to but few individuals; but the complement of properties which it will connote will be a very comprehensive one. If, on the other hand, the class be a very wide or general one, the concept will apply to a much larger number of individuals, but it will comprehend fewer attributes or properties. As application widens, meaning narrows; until from an infima species, or in English a group of the most special kind, we rise to a summum genus, or a class in which only such properties remain as are absolutely essential to thought. The process by which this is done is the process of abstraction, which consists in dismissing from consideration all properties not essential to the particular class which we may wish to form. Objects are known, it is further to be remarked, "only through their relations to other objects," and each individual object only "as a complex of such relations." No operation of thought, however, "involves the entire complement of the known or knowable properties (or relations) of a given object. In mechanics a body is considered simply as a mass of determinate weight or volume, without reference to its other physical or chemical properties"; and, in like manner, every other department of knowledge only takes account of that aspect of the object which it is necessary for the purpose in hand to study. The mind can not completely represent to itself at any one time all the properties or relations of an object; nor is it necessary that it should do so, as they can not possibly all be relevant to the same intellectual operation. Our thoughts of things are thus symbolical, because what is present to the mind at a given moment is not the object in the totality of its relations, but a symbol framed for the occasion, and embracing just those relations under which the object is to be considered. A concept in which all the relations of an object should be embraced is an obvious impossibility. We can not stand all round a thing all at once; we must choose our side, or, in other words, fix upon our point of view.
The above line of thought will be familiar to all students of philosophy, and particularly to those acquainted with the writings of Mr. Herbert Spencer. For some reason or other, however, Mr. Stallo abstains, not only here but generally throughout his book, from any