151. We have seen (Bk. VI., Ch. V.) that the idea of number is found in every understanding, and experience teaches that we employ it explicitly or implicitly in almost all our words. We scarcely speak without using the plural, and this can have no meaning without the supposition of the idea of number. Pantheism reduces all existence to an absolute unity; multiplicity either has no real existence, or is limited to phenomena, which, in the judgment of some followers of this system, contain no reality of any sort, and, in the opinion of all pantheists, can contain no substantial reality. According to them, therefore, the idea of number either has no correspondence in the reality, or it relates only to modes of being, to the various modifications of the same being, and therefore does not extend to the beings themselves, for in this system there is only one being. If this be so, how is it that the idea of number exists in our understanding? how is it that we conceive not only many modes of being, but many beings? In the system of the pantheists not only is there no multiplicity of beings, but it is impossible that there should be; why, then, has our understanding this radical vice which necessarily leads it to conceive the multiplicity of _things_, if this multiplicity is absurd? why is this ideal defect confirmed by experience which also necessarily leads us to believe that there are many distinct _things_? 152. In the system of the pantheists our understanding is only a modification, a manifestation of the only substance; but it is impossible to explain this disagreement between the phenomenon and the reality, this necessary error into which the phenomenon of the substance leads us in respect to the substance itself. If we are a mere manifestation of the unity, why do we find the idea of multiplicity as a primitive fact within us? Why this continual contradiction between the being and its appearances? If we are all one same unit, whence do we obtain the idea of number? If the phenomena of experience are only evolutions, so to speak, of this one unit, why do we feel ourselves irresistibly inclined to suppose multiplicity in the phenomena, and to multiply the _things_ in which they succeed? 153. The idea of distinction opposed to that of unity is also fundamental in our mind;[67] yet pantheism gives it no correspondence in the reality. If there is only being, if all is identical, there is nothing distinct, and the idea of distinction is a pure chimera. In this system distinction not only does not exist, but it is impossible; consequently the idea of distinction is absurd; therefore one of the primary facts of our mind is a contradiction. [67] See Bk. V., Chs. IX. and X.