THE historical source from which the main streams of Perfectionist doctrine that have invaded modern Protestantism take their origin, is the teaching of John Wesley. But John Wesley did not first introduce Perfectionism into Protestantism, nor can all the Perfectionist tendencies which have shown themselves in Protestantism since his day be traced to him. Such tendencies appear constantly along the courses of two fundamental streams of thought. Wherever Mysticism intrudes, it carries a tendency to Perfectionism with it. On Mystical ground—as, for example, among the Quakers—a Perfectionism has been developed to which that taught by Wesley shows such similarity, even in details and modes of expression, that a mistaken attempt has been made to discover an immediate genetic connection between them. Wherever again men lapse into an essentially Pelagian mode of thinking concerning the endowments of human nature and the conditions of human action, a Perfectionism similar to that taught by Pelagius himself tends to repeat itself. That is to say, history verifies the correlation of Perfectionism and Libertarianism, and wherever Libertarianism rules the thoughts of men, Perfectionism persistently makes its appearance. It is to this stream of influence that Wesleyan Perfectionism owes its own origin. Its roots are set historically in the Semi-Pelagian Perfectionism of the Dutch Remonstrants, although its rise was not unaffected by influences of a very similar character and ultimate source which came to it through the channels of Anglo-Catholicism. Its particular differentiation is determined by the supernaturalization which it shares with the whole body of modifications introduced by Wesley into his fundamental Arminianism, from which Wesleyanism, in distinction from the underlying Remonstrantism, has acquired its Evangelical character.
—Benjamin B. Warfield, The Works of Benjamin B. Warfield: Perfectionism, Part One, vol. 7 (Bellingham, WA: Logos Bible Software, 2008), 3–4.