Mrs. Cockburn, after her marriage, was entirely diverted from her studies for many years, by attending tending upon the duties of a wife and a mother, and by the ordinary cares of an encreasing family, and the additional ones arising from the reduced circumstances of her husband. However, her zeal for Mr. Lock's character and writings drew her again into the public light in 1716, upon this occasion.
Dr. Holdsworth, fellow of St. John's College in Oxford, had preached on Easter-Monday, 1719 20, before that university, a sermon on John v. 28, 29, which he published, professing in his title page to examine and answer the Cavils, False Reasonings, and False Interpretations of Scripture, of Mr. Lock and others, against the Resurrection of the Same Body. This sermon did not reach Mrs. Cockburn's hands 'till some years after; when the perusal of it forced from her some animadversions, which she threw together in the form of a letter to the Dr. and sent to him in May 1724, with a design of suppressing it entirely, if it should have the desired effect upon him. After nine months the Dr. informed her, that he had drawn up a large and particular answer to it, but was unwilling to trust her with his manuscript, 'till she should publish her own. However, after a long time, and much difficulty, she at last obtained the perusal of his answer; but not meeting with that conviction from it, which would have made her give up her cause, she was prevailed on to let the world judge between them, and accordingly published her Letter to Dr. Holdsworth, in January 1726 7, without her name, but said in the title page to be by the author of, A Defence of Mr. Lock's Essay of Human Understanding. The Dr. whose answer to it was already finished, was very expeditious in the publication of it in June 1727, in an 8vo volume, under the title of A Defence of the Doctrine of the Resurrection of the same Body, &c.
Mrs. Cockburn wrote a very particular reply to this, and entitled it, A Vindication of Mr. Lock's Principles, from the injurious Imputations of Dr. Holdsworth. But though it is an admirable performance, and she was extremely desirous of doing justice to Mr. Lock and herself, yet not meeting with any Bookseller willing to undertake, nor herself being able to support the expence of the impression, it continued in manuscript, and was reserved to enrich the collection published after her death.
Her Remarks upon some Writers in the Controversy concerning the Foundation of Moral Duty and Moral Obligation were begun during the winter of the year 1739, and finished in the following one; for the weakness of her eyes, which had been a complaint of many years standing, not permitting her to use, by candlelight, her needle, which so fully employed her in the summer season, that she read little, and wrote less; she amused herself, during the long winter-evenings, in digesting her thoughts upon the most abstract subjects in morality and metaphysics. They continued in manuscript till 1743, for want of a Bookseller inclined to accept the publication of them, and were introduced to the world in August that year, in The History of the Works of the Learned. Her name did not go with them, but they were Inscribed with the utmost Deference to Alexander Pope, Esq; by an Admirer of his moral Character; for which she shews a remarkable zeal in her letters, whenever she has occasion to mention him. And her high opinion of him in that respect, founded chiefly on his writings, and especially his letters, as well as her admiration of his genius, inspired her with a strong desire of being known to him; for which purpose she drew up a pretty long letter to him about the year 1738: but it was never sent. The strength, clearness, and vivacity shewn 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. And the worthy Dr. Sharp[3], archdeacon of Northumberland, who had these Remarks in manuscript, and encouraged the publication of them, being convinced by them, that no person was better qualified for a thorough examination of the grounds of morality, entered into a correspondence with her upon that subject. But her ill state of health at last interrupted her prosecution of it; a circumstance to be regretted, since a discussion carried on with so much sagacity and candour on both sides, would, in all probability, have left little difficulty remaining on the question.
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 confutation of that elaborate discourse; and having finished it with a spirit, elegance, and perspicuity equal, if not superior to all her former writings, transmitted her manuscript to Mr. Warburton, who published it in 8vo. with a Preface of his own, in April 1747, under the title of Remarks upon the Principles and Reasonings of Dr. Rutherforth's Essay on the Nature and Obligations of Virtue, in Vindication of the contrary Principles and Reasons inforced in the Writings of the late Dr. Samuel Clark.
The extensive reputation which this and her former writings had gained her, induced her friends to propose to her, the collecting and publishing them in a body. And upon her consenting to the scheme, which was to be executed by subscription, in order to secure to her the full benefit of the edition, it met with a ready encouragement from all persons of true taste; but though Mrs. Cockburn did not live to discharge the office of editor, yet the public has received the acquisition by her death, of a valuable series of letters, which her own modesty would have restrained her from permitting to see the light. And it were to be wished that these two volumes, conditioned for by the terms of subscription, could have contained all her dramatic writings, of which only one is here published. But as that was impossible, the preference was, upon the maturest deliberation, given to those in prose, as superior in their kind to the most perfect of her poetical, and of more general and lasting use to the world.
The loss of her husband on the 4th of January 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 71st year, after having long supported a painful disorder, with a resignation to the divine will, which had been the governing principle of her whole life, and her support under the various trials of it. Her memory and understanding continued unimpaired, 'till within a few days of her death. She was interred near her husband and youngest daughter at Long-Horsley, with this short sentence on their tomb:
Let their works praise them in the gates.
Prov. xxxi. 31.
They left only one son, who is clerk of the cheque at Chatham, and two daughters.
Mrs. Cockburn was no less celebrated for her beauty, in her younger days, than for her genius and accomplishments. She was indeed small of stature, but had a remarkable liveliness in her eye, and delicacy of complexion, which continued to her death. Her private character rendered her extremely amiable to those who intimately knew her. Her conversation was always innocent, useful and agreeable, without the least affectation of being thought a wit, and attended with a remarkable modesty and diffidence of herself, and a constant endeavour to adapt her discourse to her company. She was happy in an uncommon evenness and chearfulness of temper. Her disposition was generous and benevolent; and ready upon all occasions to forgive injuries, and bear them, as well as misfortunes, without interrupting her own ease, or that of others, with complaints or reproaches. The pressures of a very contracted fortune were supported by her with calmness and in silence; nor did she ever attempt to improve it among those great personages to whom she was known, by importunities; to which the best minds are most averse, and which her approved merit and established reputation mould have rendered unnecessary.