Discovered this today in the sermon "Regeneration and Conversion" on John 1:13 by Samuel Hopkins (1721-1803), disciple of Jonathan Edwards and New England pastor:
This regeneration of which I am speaking consists in a change of the will or heart. The truth of this observation appears from the foregoing, as it is a plain consequence from it. If the depravity and corruption of the heart is the only ground of the necessity of regeneration, then regeneration consists in removing this depravity, and introducing opposite principles, and so laying a foundation for holy exercises. But depravity or sin lies wholly in the heart, and not in the intellect or faculty of understanding, considered as distinct from the will, and not including that. So far as the will is renewed or set right, the whole mind is right; for sin and holiness lie wholly in this. If moral depravity does not lie in, or properly belong to, the faculty of the understanding or the intellect, as distinguished from the will, or heart, then that operation of the Spirit of God, by which this is in some measure removed and moral rectitude introduced, does not immediately respect the understanding, but the will or heart, and immediately produces a change in the latter, not in the former. It is allowed by all, I suppose, that regeneration does not produce any new natural capacity or faculty in the soul. These remain the same after regeneration that they were before, so far as they are natural. The change produced is a moral change, and, therefore, the will or heart must be the immediate subject of this change, and of the operation that effects it; for every thing of a moral nature belongs to the will or heart.
As depravity or sin began in the will, and consists wholly in the irregularity and corruption of that, so regeneration, or a recovery from sin in the renovation of the mind, must begin here, and wholly consists in the change and renewal of the will. There is not, nor can there be, any need of any other change, in order to the complete renovation of the depraved mind, and its recovery to perfect holiness. Therefore, I think I have good grounds to assert, that in regeneration the will or heart is the immediate subject of the divine operation, and so of the moral change that is effected hereby. The Spirit of God in regeneration gives a new heart, an honest and good heart. He begets a right and good taste, temper, or disposition, and so lays a foundation for holy exercises of heart.
--E. Hindson, ed., Introduction to Puritan Theology: A Reader (Grand Rapids: Baker, 1976), 179-180.