 The human soul exists or we exist. Since nothing is without a sufficient reason why it is rather than is not, a sufficient reason must be given why our soul exists, or why we exist. Now this reason is contained in ourselves or in some other being diverse from us. But if you maintain that we have the reason of our existence in a being which, in turn, has the reason of its existence in another, you will not arrive at the sufficient reason unless you come to a halt at some being which does have the sufficient reason of its own existence in itself. Therefore, either we ourselves are the necessary being, or there is given a necessary being other and diverse from us. Consequently, a necessary being exists (NT: I, §24).