69. It must be observed that in all this argument, I abstract the nature of the substance of the soul, and only purpose to demonstrate that we must admit something constant in the midst of the variety of the phenomena, and common to them all. Call it a tie, a form, an act of consciousness, or what you will, it is either something real or it is not. If it is not something real, whoever expresses it, employs a word without any meaning: if it is something real, the substantiality of the soul is acknowledged, because a permanent reality is admitted in the midst of the variety of the phenomena. We, who admit this substantiality, do not pretend that the soul can be given in sensible intuition, nor that we can express in an exact definition its internal properties abstracted from the phenomena which we experience in it. What we say is, that we know its real existence, its permanence, and its numerical identity in the midst of the succession and diversity of the phenomena. Therefore from the moment that it is admitted that there is within us something real, permanent, and numerically identical in the midst of diversity, the substantiality of the soul, which we defend, is admitted. Disputes may arise on the distinctive character of its nature; whether it is or is not a force, as Leibnitz maintained, whether its essence consists in thought, as was the opinion of Descartes: but these questions are foreign to the matter now in hand. Is there something real and permanent amid the variety of internal phenomena? If there is not, the consciousness of numerical identity is absurd; if there is, then the substantiality of the soul is demonstrated.