CIII Incontestable Proofs Against the Spirituality of the Soul
The dogma of the immortality of the soul assumes that the soul is a simple substance, a spirit; but I will always ask, what is a spirit? It is, you say, a substance deprived of expansion, incorruptible, and which has nothing in common with matter. But if this is true, how came your soul into existence? how did it grow? how did it strengthen? how weaken itself, get out of order, and grow old with your body? In reply to all these questions, you say that they are mysteries; but if they are mysteries, you understand nothing about them. If you do not understand anything about them, how can you positively affirm anything about them? In order to believe or to affirm anything, it is necessary at least to know what that consists of which we believe and which we affirm. To believe in the existence of your immaterial soul, is to say that you are persuaded of the existence of a thing of which it is impossible for you to form any true idea; it is to believe in words without attaching any sense to them; to affirm that the thing is as you claim, is the highest folly or assumption.