Robert Barclay (December 23, 1648 – October 3, 1690) was an eminent writer known for his writings in defence of the Religious Society of Friends (Quakers), which led him to be known as "Robert the Apologist". A member of the Clan Barclay, he was also governor of the East Jersey colony in North America through most of the 1680s.
"At length Robert Barclay, a native of Scotland, presented to the king, in 1675, his Apology for the Quakers; a work as well drawn up as the subject could possibly admit. The dedication to Charles II., instead of being filled with mean, flattering encomiums, abounds with bold truths and the wisest counsels. Thou hast tasted, says he to the king, at the close of his “Epistle Dedicatory,” of prosperity and adversity: thou hast been driven out of the country over which thou now reignest, and from the throne on which thou sittest: thou hast groaned beneath the yoke of oppression; therefore hast thou reason to know how hateful the oppressor is both to God and man. If, after all these warnings and advertisements, thou dost not turn unto the Lord, with all thy heart; but forget Him who remembered thee in thy distress, and give thyself up to follow lust and vanity, surely great will be thy guilt, and bitter thy condemnation. Instead of listening to the flatterers about thee, hearken only to the voice that is within thee, which never flatters. I am thy faithful friend and servant, Robert Barclay.
Voltaire, Philosophical Letters
Barclay was born at Gordonstoun in Moray, Scotland. His father Colonel David Barclay of Urie had served under Gustavus Adolphus, and pursued a somewhat tortuous course through the troubles of the civil war. His mother was Katherine Gordon (1620–1663) the daughter of Sir Robert Gordon 1st Bart of Gordonstoun (1580-1654). He was the eldest of five children.
Robert was sent to finish his education at the Scots College, Paris, of which his uncle Robert Barclay (1611/12–1682), was Rector. His uncle offered to make him his heir if he would remain in France, and continue in the Roman Catholic Church, but in 1667, respecting his mother's dying wish, he returned to Scotland. In 1665 his father was committed to prison in Edinburgh on account of his interregnum activities, and here he shared a cell with John Swinton who converted him to Quakerism. Robert, visiting his father, was persuaded to attend a Quaker meeting, and according to his own account it was the experience of the meeting itself, and not any particular message, which persuaded him to join. Soon afterwards he began to write in defence of the movement, by publishing in 1670 Truth cleared of Calumnies, and a Catechism and Confession of Faith (1673). In 1670 he 'married another Quaker, Christian Mollison (c.1651–1724), of Aberdeen. They had seven children: three sons and four daughters.
Barclay was an ardent theological student, and soon became the leading apologist of the new doctrine, winning his spurs in a controversy with one William Mitchell. The publication of fifteen Theses Theologiae (1676) led to a public discussion in Aberdeen, each side claiming a victory.The most prominent of the Theses was that bearing on immediate revelation, in which the superiority of the Inward Light of Christ to reason or scripture is sharply stated. He was a strong supporter of George Fox in the controversies that tore into Quakers in the 1670s. His greatest work, An Apology for the True Christian Divinity, published in Latin at Amsterdam in 1676, was a statement of the grounds for holding certain fundamental positions laid down in the Theses. It was translated by its author into English in 1678, and is claimed to be "one of the most impressive theological writings of the century" .
It, however, failed to arrest the persecution of the Quakers, and Barclay, on returning from Europe, where he travelled extensively (once with William Penn and George Fox), and had several interviews with Elisabeth, Princess Palatine, was several times thrown into prison.
In later years he had much influence with James VII and II, who as Duke of York had given New Jersey to Sir George Carteret and John Berkeley, 1st Baron Berkeley of Stratton. After Carteret's death his half (East Jersey) was sold in 1682 to twelve people, eleven of whom were members of the Society of Friends. One of these was William Penn, and after expanding to include a larger number of proprietors, the group elected Barclay to be the governor, though he never went to the colony. He is said to have visited James with a view to making terms of accommodation with William of Orange, whose arrival was then imminent.
Barclay was in London for the last time in 1688, and visited King James II. Being with him near a window, the king looked out and observed that "the wind was then fair for the prince of Orange to come over." to which Barclay replied "it was hard that no expedient could be found to satisfy the people." The king declared he would "do any thing becoming a gentleman, except parting with liberty of conscience, which he never would whilst he lived." 
An Apology for the true Christian divinity is set out formally in 15 propositions. Each proposition is followed by one or more proofs, then by objections and answers to the objections. Although Barclay is arguing for the supremacy of personal experience over scripture, he accepts the use of the scriptures in arguments over doctrine, and therefore bolsters his argument with extensive references not only to the Bible but to the Early Fathers and others.
Perhaps the most extraordinary success of the work came in the 19th century when a group of people in Kolkata were converted to Quakerism apparently by reading the Apology. Their 1861 appeal to London Yearly Meeting for more personal assistance met with no success, but Australian Quakers came to their aid.
- Voltaire The Works of Voltaire, Vol. XIX (Philosophical Letters) THE RELIGION OF THE QUAKERS. paragraph 431
- History of the religious Society of friends, from its rise to the year 1828 By Samuel Mcpherson Janney
- said by Leslie Stephen, according to The age of Dryden by Richard Garnett, on Googlebooks p226.
- A short account of the life and writings of Robert Barclay By Joseph Gurney Bevan
- Sykes, M. Quakers in India: a forgotten century. Allen & Unwin. 1980. pp 42—48.
- An Apology For the True Christian Divinity by Robert Barclay
- Encyclopedia Britannica
- The Anarchy of the Ranters, and other Libertines. The hierarchy of the Romanists, and other pretended Churches equally refused, and refuted in a two-fold Apology for the Church and People of God, called in derision Quakers. Wherein they are vindicated from those that accuse them of disorder and confusion on the one hand, and from such as calumniate them with tyranny and imposition on the other: Shewing, that as the true and pure Principles of the Gospel are restored by their testimony; so is also the ancient Apostolick Order of the Church of Christ re-established among them, and settled upon its right basis and Foundation. By Robert Barclay.