The Father and Son in the Trinity are therefore father and son not in a figurative sense, but in a strictly literal sense. The Father is a real father in relation to the Son, the Son is a real son in relation to the Father, or to God as the Father. The essential personal distinction between them consists only in this, that the one begets, the other is begotten. If this natural empirical condition is taken away, their personal existence and reality are annihilated. The Christians--we mean of course the Christians of former days, who would with difficulty recognise the worldly, frivolous, pagan Christians of the modern world as their brethren in Christ--substituted for the natural love and unity immanent in man a purely religious love and unity; they rejected the real life of the family, the intimate bond of love which is naturally moral, as an undivine, unheavenly, i.e., in truth, a worthless thing. But in compensation they had a Father and Son in God, who embraced each other with heartfelt love, with that intense love which natural relationship alone inspires. On this account the mystery of the Trinity was to the ancient Christians an object of unbounded wonder, enthusiasm, and rapture, because here the satisfaction of those profoundest human wants which in reality, in life, they denied, became to them an object of contemplation in God. [47] It was therefore quite in order that, to complete the divine family, the bond of love between Father and Son, a third, and that a feminine person, was received into heaven; for the personality of the Holy Spirit is a too vague and precarious, a too obviously poetic personification of the mutual love of the Father and Son, to serve as the third complementary being. It is true that the Virgin Mary was not so placed between the Father and Son as to imply that the Father had begotten the Son through her, because the sexual relation was regarded by the Christians as something unholy and sinful; but it is enough that the maternal principle was associated with the Father and Son.