"To the understanding of this subject, there is no necessity for an anxious discussion, (which in no small degree perplexed the ancient doctors), as to whether the soul of the child comes by transmission from the soul of the parent. It should be enough for us to know that Adam was made the depository of the endowments which God was pleased to bestow on human nature, and that, therefore, when he lost what he had received, he lost not only for himself but for us all. Why feel any anxiety about the transmission of the soul, when we know that the qualities which Adam lost he received for us not less than for himself, that they were not gifts to a single man, but attributes of the whole human race? There is nothing absurd, therefore, in the view, that when he was divested, his nature was left naked and destitute that he having been defiled by sin, the pollution extends to all his seed. Thus, from a corrupt root corrupt branches proceeding, transmit their corruption to the saplings which spring from them. The children being vitiated in their parent, conveyed the taint to the grandchildren; in other words, corruption commencing in Adam, is, by perpetual descent, conveyed from those preceding to those coming after them. The cause of the contagion is neither in the substance of the flesh nor the soul, but God was pleased to ordain that those gifts which he had bestowed on the first man, that man should lose as well for his descendants as for himself.
"The Pelagian cavil, as to the improbability of children deriving corruption from pious parents, whereas, they ought rather to be sanctified by their purity, is easily refuted. Children come not by spiritual regeneration but carnal descent. Accordingly, as Augustine says, "Both the condemned unbeliever and the acquitted believer beget offspring not acquitted but condemned, because the nature which begets is corrupt." Moreover, though godly parents do in some measure contribute to the holiness of their offspring, this is by the blessing of God; a blessing, however, which does not prevent the primary and universal curse of the whole race from previously taking effect. Guilt is from nature, whereas sanctification is from supernatural grace.""John Calvin. Institutes of Christian Religion