4. It is contrary to our experience of nature, that He should be born man and still remain God; but it accords with the tenor of our expectation, that being born man, He still remained God, for when the higher nature is born into the lower, it is credible that the lower should also be born into the higher. And, indeed, according to the laws and habits of nature, the working of our expectation even anticipates the divine mystery. For in every thing that is born, nature has the capacity for increase, but has no power of decrease. Look at the trees, the crops, the cattle. Regard man himself, the possessor of reason. He always expands by growth, he does not contract by decrease; nor does he ever lose the self into which he has grown. He wastes indeed with age, or is cut off by death; he undergoes change by lapse of time, or reaches the end allotted to the constitution of life, yet it is not in his power to cease to be what he is; I mean that he cannot make a new self by decrease from his old self, that is, become a child again from an old man. So the necessity of perpetual increase, which is imposed on our nature by natural law, leads us on good grounds to expect its promotion into a higher nature, since its increase is according to, and its decrease contrary to, nature. It was God alone Who could become something other than before, and yet not cease to be what He had ever been; Who could shrink within the limits of womb, cradle, and infancy, yet not depart from the power of God. This is a mystery, not for Himself, but for us. The assumption of our nature was no advancement for God, but His willingness to lower Himself is our promotion, for He did not resign His divinity but conferred divinity on man.