Common grace is “the grace of God by which he give people innumerable blessings that are not part of salvation” (Grudem, Systematic Theology, p. 657). Common grace is essentially God’s kindness, even to people who are not believers.
Remember, all people are sinners and are therefore immediately worthy of God’s judgment. Yet God withholds his judgment, has provided for us an orderly world to live in, provides food/air/water/life for all people, brings about some level of moral goodness even from unbelievers (for instance, even though they are totally depraved they do not intentionally run over little old ladies crossing the street, and they might even help them), establishes human government, and more.
But where does the doctrine of common grace fit in the categories of systematic theology? Depends on who you ask.
Under Theology Proper (the doctrine of God himself) – It is a part of God’s rule in his created world (Erickson, p. 401-402, 294, 303; Reymond, pp. 402-03).
Under Soteriology (the doctrine of salvation) – It is preparatory for God’s work of special grace, sometimes called saving grace or efficacious grace (C. Hodge, 3:654ff.; A.H. Strong; 3:783; Moody Handbook of Theology, pp. 334-35; Grudem, pp. 657-665; Shedd, pp. 774ff.).
Under Pneumatology (the doctrine of the Spirit) – It is part of the Spirit’s work of control and conviction in the world (Snoeberger; McCune (Systematic Theology II forthcoming I assume); Walvoord [The Holy Spirit, pp. 107ff.; he connects it with providence and sovereignty on p. 107]).
Can you help by enlarging this list of where theologians of various stripes stand on the placement of common grace in systematic theology? (Or correct me if I have misunderstood one of the few I have above.)
As for me, Theology Proper seems to be the best place for it. The soteriological aspect of it seems too narrow. Only in the broadest sense of preparation for salvation does it seem that it is soteriological. It also seems too broad to tie solely to the work of the Spirit since it seems that some of it is not directly connected with the work of the Spirit (e.g., rain, food). It seems that it is the work of God’s providence to mitigate the effects of sin and delay judgment in the world, while making the world inhabitable for his creation, particularly his image bearers.
Can you help with an argument as to why one category would be better than another?

