(Mrs Catharine), was the daughter of Captain David Trotter, a Scotch gentleman. He was a commander in the royal navy in the reign of Charles II, and at his death left two daughters, the youngest of whom, Catharine, our celebrated author, was born in London, August 1679. She gave early marks of her genius; and learned to write, and also made herself mistress of the French language, by her own application and diligence, without any instructor; but she had some assistance in the study of the Latin grammar and logic, of which latter she drew up an abstract for her own use. The most serious and important subjects, and especially religion, soon engaged her attention. But notwithstanding her education, her intimacy with several families of distinction of the Roman persuasion, exposed her, while very young, to impressions in favour of that church; which not being removed by her conferences with some eminent and learned members of the church of England, she embraced the Roman communion, in which she continued till the year 1707. In 1695, she produced a tragedy called Agnes de Castro, which was acted at the theatre-royal when she was only in her 17th year. The reputation of this performance, and the verses which she addressed to Mr Congreve upon his Mourning Bride, in 1697, were probably the foundation of her acquaintance with that celebrated writer. Her second tragedy, Fatal Friendship, was acted in 1698, at the new theatre in Lincoln's-Inn-Fields. This tragedy met with great applause, and is still thought the most perfect of her dramatic performances. Her dramatic talents not being confined to tragedy, she brought upon the stage, in 1701, a comedy called Love at a Loss, or Most Vows carry it. In the same year she gave the public her third tragedy, entitled The Unhappy Patient, acted at the theatre royal in Drury-lane. But poetry and dramatic writing did not so far engross the thoughts of our author but that she sometimes turned them to subjects of a very different nature; and distinguished herself in an extraordinary manner in defence of Mr Locke's writings; a female metaphysician being a remarkable phenomenon in the republic of letters.

She returned to the exercise of her dramatic genius in 1703, and fixed upon the revolution of Sweden, under Gustavus Erickson, for the subject of a tragedy. This tragedy was acted, in 1706, at the Queen's theatre in the Hay-Market. In 1707, her doubts concerning the Roman religion, which she had so many years professed, having led her to a thorough examination of the grounds of it, by consulting the best books on both sides of the question, and advising with men of the best judgment, the result was a conviction of the fallacies of the pretensions of that church, and a return to that of England, to which she adhered during the remainder of her life. In 1708, she was married to the Rev. Mr Cockburn, then curate of St Dunstan's in Fleet-street, but he afterwards obtained the living of Long-Horley, near Morpeth in Northumberland. He was a man of considerable abilities; and, among several other things, wrote an account of the Mosaic Deluge, which was much approved by the learned.

Mrs Cockburn's remarks upon some writers in the controversy concerning the foundation of moral duty and moral obligation, were introduced to the world, in August 1743, in the Literary Journal, intitled The History of the Works of the Learned. The strength, clearness, and vivacity shown in her remarks upon the most abstract and perplexed questions, immediately raised the curiosity of all good judges about the concealed writer; and their admiration was greatly increased when her sex and advanced age were known. Dr Rutherforth's Essay on the Nature and Obligations of Virtue, published in May 1744, soon engaged her thoughts; and notwithstanding the asthmatic disorder which had seized her many years before, and now left her small intervals of ease, she applied herself to the composition of that elaborate discourse, and finished it with a spirit, elegance, and perspicuity equal, if not superior, to all her former writings.

The loss of her husband in 1748, in the 71st year of his age, was a severe shock to her; and she did not long survive him, dying on the 11th of May 1749, in her