The Princeton Mode.
The theologians of Princeton set forth the following as the mode in which man caused his own depraved nature:
God created Adam with a perfectly holy nature. Adam sinned and ruined his own nature. God had previously “made a covenant with Adam, not only for himself, but for all his posterity, or in other words, Adam having been placed on trial, not only for himself, but also for his race, his act was in virtue of this relation regarded (by God) as our act. God withdrew from us as he did from him; in consequence of this withdrawal, we begin to exist in moral darkness, destitute of a disposition to delight in God and prone to delight in ourselves and in the world. The sin of Adam therefore ruined us; and the intervention of the Son of God for our salvation is an act of pure, sovereign, and wonderful grace.”
The above is extracted from a standard writer of the Princeton Theological Seminary, and expresses the views of the Old School Presbyterian church in this matter.
It is simply saying that man made his own depraved nature, inasmuch as God regarded Adam's act as our act when it was not, being performed before we existed, and that he punished us by withdrawing from us, as he did from Adam, and thus our nature becomes ruined and totally depraved.
The Constitutional Transmission Mode.
The next way in which man is made to be the author of his own nature is called the constitutional transmission mode. It is as follows:
God made Adam with a perfectly holy mind, and then Adam sinned and ruined his own nature. In consequence of this act, God established such a constitution of things that Adam transmitted his depraved nature to all his posterity, just as bodily diseases are transmitted from parents to children.
In this way man is said to be the author of his own depraved nature, meaning, by man, Adam.
In this case it is conceded that God had power to make such a constitution of things as that all human minds would begin existence, as Adam did, with perfectly holy minds, and that instead of this, he chose that such a depraved nature should be transmitted to all as would insure universal sin. And yet it is claimed that by this mode, man, and not God, is shown to be “the author of sin.”
This is the mode adopted by most of the Andover and New Haven theologians.
Dr. Edward Beecher, in his work “The Conflict of Ages,” advocates the idea that man ruined his own nature in a preëxistent state before Adam. But the evidence of this has not yet been presented.
Thus all who do not take the Catholic mode of mystery and sovereignty maintain that man made his own depravity of nature, either in or by or before Adam.