[14] There is in this work an interesting passage ("Truth Triumphant" pp. 29, 30), in which the view of singing held by the early Friends is set forth, which will correct some mistaken impressions. Barclay maintains "that singing is a part of God's worship, and is warrantably performed amongst the saints, is a thing denied by no Quaker so-called, and is not unusual among them, whereof I have myself been a witness, and have felt the sweetness and quickening virtue of the spirit therein, and at such occasions ministered." But they object to a mixed congregation of believers and unconverted persons singing words which in the mouths of many must be lies. (See also the Apology, Prop. II., paragraph 26, &c.)
But once launched on the stormy sea of controversy, there was no more rest for him. W. Mitchell acknowledged the authorship of the "Dialogue," and returned to the attack in some "Considerations." This drew forth in rejoinder "William Mitchell unmasked," published 1672. Here we find a more mature style, a fulness of matter, and an ease and power in statement, that are only excelled in the Apology. Says the writer in the Biographia Brittanica: "In this work our author discovers an amazing variety of learning; which shows how good a use he made of his time at Paris, and how thorough a master he was of the scriptures, the fathers, and ecclesiastical history; and with how much skill and judgment he applied them." And a recent writer says "Poor William Mitchell is not only unmasked but extinguished."
Some have imagined that Robert Barclay and his friend William Penn introduced into Quakerism a new, more reasonable, and more scholarly tone. But comparing the sixteen or eighteen years of Quakerism before these worthies accepted it, with the subsequent period when they have been supposed to affect its counsels, effectually disposes of this view. Neither in doctrine nor in practice is there any material difference. Quakerism had its scholars before them. Their pre-eminence was rather in popular gifts than in learning, and in statement and illustration of Quaker views rather than in their discovery or modification. As regards the positions of Quakerism that have given offence, Barclay and other scholarly converts accepted them in toto. They speak of the "apostacy" of the churches, and of Quakerism as the only true church. They speak boldly of the spiritual gifts of the brethren. They are severe on "hireling" priests. They argue that justification is one with sanctification. Most of the important passages referring to the authority of Holy Scripture, Barclay applies to the light within.