Barclay's Apology has been spoken of as a system of Divinity. It is nothing of the kind, but simply an exhaustive treatise on the points in which Quakerism differs from the current evangelical Christianity of his day. The point is of importance, because otherwise the reader may be led astray both by the omissions from the work, and by the proportions allotted to different subjects. He must look elsewhere, for instance, for proofs that the early Friends were substantially orthodox in their views of the Trinity. Much has been said about the Apology being framed on a plan similar to the Assembly's Catechism, and being indeed a reply to it. But that Catechism itself is on the plan of Calvin's Institutes, the trusted guide of Scotch orthodoxy. It would be an interesting point to trace the relation between the Institutes and the Apology. As to the Calvinistic controversy, a recent writer says, "No man ever gave Calvinism such mighty shakes as Barclay did. And he shook it from within. He understood it. As the religion of his country he had entered into it and made himself master of it. His controversy with Calvin was on fundamental principles." (Theological Review, 1874, p. 553). These assertions must be modified by remembering that, as we have seen, almost from childhood Barclay disliked Calvinism, so that whilst he might effectually combat some of its positions, he was little likely to do justice to its strong points, and can hardly be said to have shaken it from within. The Arminianism of the Catholic Church would strengthen his instinctive dislike, so that though he found the Quakers Arminians, he in nowise owed his convictions on this point to them. The style of the Apology is beautifully clear. The best proof of its simplicity is to be found in the fact that many of the artisan class have so followed its reasonings as to be led to accept Quakerism by this book alone. Probably it has brought more converts to Quakerism than any other book that ever was written. It is grand in its efficient handling of great questions without any appearance of labour or effort. There is a cumulative power in many of the paragraphs that is very effective; epithet piled on epithet, clause following up clause like the waves of the incoming tide, until mind and heart are alike borne along by its rush. The thought is made to stand out not only boldly and clearly, but clothed with that subtle power which is only wielded by the transparently honest and the intensely earnest. At times the writer condescends to brusque vehemence or touching appeal to his own experience.