Bearing this in mind, we shall experience little difficulty in determining the conditions under which the representation and conception of a material object as real are possible. A representation of such an object being an exhibition of the deliverances of sense respecting it, it is plain that nothing can be represented as objectively real, except in terms of experience. And, since our experience is only of the singular and particular, it is also evident that a concept cannot be represented in the mind as objectively real. Thus, matter as such is not a real thing, but a concept; it cannot be "realized" in thought. We can realize, or imagine, or represent as actual, only some one particular thing, with all its accidents of particularity—as of particular dimensions, of a particular color, of a particular temperature, and as being either at rest (i. e., in a state of tension) or in motion. All attempts mentally to represent the reality, in and by itself, of any of the elements into which an individual object is analyzed by the process of abstraction are necessarily futile. The history of speculation is full of attempts of this sort—of attempts to grasp the "thing" as distinct from its properties, the substance apart from its attributes, or, conversely, the attributes apart from their unity, the substance. It is this old error which lies hid in the reasoning of Prof. Tyndall in the passage quoted at the beginning of this article. And the same error lurks in Faraday's endeavor to represent matter as a mere complex of forces. In the one case the properties are imagined to be added to the thing, or the attributes are supposed to be implanted in the substance, as the plums are stuck into the pudding, so that the substance will remain after the attributes are removed; in the other case the substance is looked upon as a mere sum of the attributes—the pudding is thought to be all plums, which not only have a reality by themselves, but which are alone real. That this apparently trivial illustration is entirely apposite, is readily shown by a reference to the grounds upon which Faraday rejects the hypothesis of corpuscular atoms. While the advocates of this hypothesis seek to remove the plums and to retain the pudding, Faraday, on the contrary, takes the plums, and then asks, "Where is the pudding?" "What do we know," he says (Tyndall, "Faraday as a Discoverer," p. 123, American ed.)" of the atom apart from its force? You imagine a nucleus which may be called a, and surround it by forces which may be called m; to my mind, the a or nucleus vanishes, and the substance consists in the powers of m. And, indeed, what notion can we form of the nucleus independent of its powers? What thought remains on which to hang the imagination of an a independent of the acknowledged forces?"
The true root of all those errors is a total misconception of the nature of reality. All the reality we know is not only spatially finite, but limited in all its aspects; its whole existence lies in relation and contrast, as I shall show more at length in the next article. We know nothing of force, except by its contrast with mass, or (what is the same