There are not then many ideas; there is one Idea, which is Thought. Only in a metaphorical sense can we consider them as things; and, properly speaking, they are the human person itself as actualised in thought, which is busily occupied in the construction of knowledge. They are an indivisible unity, in which each idea is found collaborating with every other one so as to answer the questions which Thought constantly propounds. They are the human person, not the persons; for we have already concluded that only in an abstract sense is it possible to speak of many persons; concretely there is but one universal Person which is not multiplicable. There are not, then, going back to our original division, persons and things, material and spiritual. At the most there is one person, Man, and there are the material things which constitute this nature, as it occupies space, and in which we too believe we have a place, in as much as we consider ourselves beings of nature. Nothing beyond this can be conceived: on one side a sole immultiplicable reality, on the other a manifold reality, indefinitely divisible. Here we might perhaps stop considering the special interest that called forth this inquiry. For no one could possibly suppose for a moment that culture could be placed in the midst of material things rather than in the spiritual reality which is a person. However, since the intimate nature of this spiritual reality which we call culture is not yet clearly revealed, we must continue our investigations, and give more attention to this division which for a moment we thought might be final. I mean the division of the world into persons and things: the equipoise of spirit and matter. Do we really _think_ this matter as we say we do, and which we believe we are justified in opposing to the spirit, in as much as the spirit is unity or universality, and matter, in its entirety, in every one of its parts, in everything, is an indefinite multiplicity? Matter can in truth be thought only on condition that it be possible to think multiplicity, that pure multiplicity which is the characteristic quality of matter. What then is the meaning of multiplicity? In absolute terms we call multiple that which consists of elements each one of which is quite independent of all the others, and absolutely devoid of any and every relationship with them. The materialist conceived the world as an aggregate of atoms, separated one from the other and having no reciprocal relevance of any sort whatsoever. In the world of pure quantity, which is the same as absolute multiplicity, mathematical science claims the knowledge of units indifferent to their nexus, and therefore susceptible of being united and separated, of being summed up and divided, without any alteration taking place within the individual unit itself. Numerical units are therefore pre-eminently irrelative.