Proslogium and Monologium/Monologium/Chapter41

Chapter XLI
He most truly begets, and it is most truly begotten.

But it will be impossible to establish this proposition, unless, in equal degree, he most truly begets, and it is most truly begotten. As the former supposition is evidently true, so the latter is necessarily most certain. Hence, it belongs to the supreme Spirit most truly to beget, and to his Word to be most truly begotten.