Starting a new Elevations on the Mysteries by Bossuet, 2,1:
Why should God not have had a Son? Why should this happy nature lack this perfect fecundity that she gives to her creatures? The name of Father, is it so dishonouring and so unworthy of the first being, that he cannot arrange according to his natural characteristic? I who makes others have children, cannot not I have a child all the same? and if it is beautiful to have them, to make oneself children by adoption, is it not more beautiful and greater to generate them by nature?
I well know that an immortal nature does not have the need like a mortal and fragile one to renew itself, to perpetuate in substituting in his place children when one leaves the world, when one departs. But in himself, independently of this necessary reparation, is it not beautiful to produce another himself by abundance, by fulness, as the result of an endless communication, in a word by fertility and by the richness of a happy and perfect nature?
It is by participation in this happy fertility that man is fertile. When he lived immortal, according to the first design of his creation; when it pleased his creator for him to complete his happiness in his allotted time on earth, one always extends himself, it is beautiful to be fertile and to engender from himself and his own substance another. When this fertile efficacy is turned loose in its original and primitive state, it will be able to end when God wants it to, when the number of men which he wants to make happy is complete: but of itself, it will always be looked upon as rich and complete. And where does this perfection come, if not from that of God always fertile in himself, and always father?
When the Sage pronounced these words: Who is he who is lifted up at the highest of the Heavens by his power, and who goes down endlessly by his cares? Who holds the winds in his hands? Who holds the sea in its limits and measures the ends of the earth? What is his name and who is the name of his son, if you know it? This is not a simple idea and words in the air: he claims to propose a mystery worthy of God, and something true and real, but at the same time incomprehensible. In his infinite nature, he saw a father whom one cannot understand and a son whose name was unknown. There was no question about naming or knowing him, because one knew that he was ineffable.
That is to say that to know the Son of God, it is necessary to raise up above the senses and of everything which can be known and named among men: it is necessary to take away all imperfection in the name of the son to leave only this: that the son is of the same nature as his father, without which the name of son will not stand. A child one day is not less of a man than his father: he is a man less formed, less perfect: but as less of a man, this cannot be and their beings cannot be so divided. But if a man and a son of a man can be imperfect, a God and a son of God cannot be so. Let us take away this imperfection, from the Son of God, who lives in another way, otherwise put by our fathers in the council of Nicea from the beginnings of Christianity: that he is God from God, light from light, true God from true God: perfect son of a perfect father: from a father who, not waiting to be old enough to be fertile, is father from what he is: who was never without his son: of whom the son has nothing degenerating, nothing imperfect, nothing to have to wait for until he is older, for all of this is nothing but the defect of the birth of men. God the Father has no need to associate himself to any other thing but himself to be father and fertile: he does not produce another outside of himself, because nothing which is outside of God is God. God thus conceives within himself, he carries in himself his fruit which is co-eternal with him. Again he is only father and the name of mother which is attached to imperfect and degenerating sex is not proper to him, all the while he has a maternal type of womb where he carries his son: I have, he says, generated you today from a material womb; ex utero. And the son calls himself the only son which is in the womb of the Father: a character uniquely proper to the Son of God. For where is the son, unless he is always in his father and never leaves his womb? His conception was not distinguished by his birth; the fruit he carried was perfect from when he was conceived, and he never left the womb in which he was carried. Who is carried in an immense womb, is from the start just as large and immense as the womb where he was conceived and never left. God generated him, God received him into his womb, God conceived him, God carried him, God gave him birth: and the eternal wisdom which was nothing else than the son of God was attributed by Solomon as having been conceived and given birth: and all of this is only the same thing. God will only have this son, because he is perfect, and he cannot have two: one long and unique birth from this perfect nature and empties all the fertility and clothes him in all the love. This is why the Son of God calls himself Unique, the unique Son, Unigenitus: by which he shows at the same time that he is the Son, not by grace or adoption, but by nature. And the Father confirmed this word about the Son from on high by making this voice leave heaven: This is my well-loved son in which I am pleased: it is my Son, I have only him; and, from all eternity I have given him and give him all my love without end.