Mr Ferguson was intended for the church, and had not pursued the study of divinity beyond two years, when, in 1744, Mr Murray, brother to Lord Elibank, offered him the situation of deputy chaplain, under himself, in the 42d regiment. In order, however, to obtain a license as a preacher in the church of Scotland, it was necessary at that time to have studied divinity for six years, and although the fact of Ferguson having some slight knowledge of the Gaelic language, might have entitled him to have two of these years discounted, still no presbytery was authorized to have granted him his license. He was therefore obliged to apply to the general assembly of the church of Scotland, when in consideration of the high testimonials which he produced from several professors, a dispensation was granted in his favour, and having passed his trials, he obtained his license as a preacher; immediately after which he joined his regiment, then in active service in Flanders. In a short time he had the good fortune to be promoted to the rank of principal chaplain.

Mr Gibbon has declared that the manoeuvres of a battalion of militia, of which he was colonel, had enabled him to comprehend and describe the evolutions of the Roman legion; and no doubt Mr Ferguson owed his knowledge of military affairs by which he was enabled to give such distinctness and liveliness to his descriptions of wars and battles, to the experience which he acquired while with his regiment on the continent. Nor did his service prove less beneficial to him by throwing open a wide and instructive field of observation of the human character, and imparting a practical knowledge of the mainspring of political events.

On the peace of Aix-la-Chapelle, Mr Ferguson obtained leave of absence when he visited his native country. At home, he spent his time partly in Perth-shire, wandering about in comparative idleness, enjoying the beautiful scenery which surrounded his father’s manse, and partly in the capital where he renewed his acquaintance with the friends of his youth. About this period he solicited the Duke of Athol for the living of Caputh, a beautiful and retired parish near Dunkeld, in Perthshire; he was, however, unsuccessful in his application, and it was owing, perhaps, to this disappointment that he did not ask the living of Logie Bait, on the death of his father, which took place shortly after. Having rejoined his regiment, he seems thenceforward to have abandoned all intention of undertaking a parochial charge. Indeed, his talents did not peculiarly fit him for the office of a preacher; for although he had acquired a great facility in writing, his sermons were rather moral essays than eloquent discourses. This, in a great measure, disqualified him for becoming a favourite with a presbyterian congregation, in which so much always depends on the preacher’s capacity to excite and sustain a spirit of devotion among his hearers, by the fidelity, earnestness, and energy of his exhortations, and the fervour of his prayers. Although thus unfitted by the nature of his genius to shine as a preacher, Mr Ferguson’s great abilities, his polished manners, and the benevolence of his disposition, peculiarly fitted him for taking a prominent part in literature and in private society.

In the year 1757, Mr. Ferguson resigned the chaplaincy of the 42d regiment, after which he was employed for upwards of two years as private tutor in the family of the earl of Bute; and in the year 1759, he was chosen professor of natural philosophy, in the university of Edinburgh; which chair he retained until the year 1764, when he obtained the professorship of moral philosophy—a chair much better suited to his genius, and to the course of study which he had pursued.

In 1766, he published his Essays on Civil Society. The object of this work is,—according to the favourite mode of the literary men with whom Ferguson associated,—to trace men through the several steps in his progress from barbarism to civilization. This, which was his first publication, contributed not a little to raise Mr Ferguson in public estimation, and the university of Edinburgh hastened to confer on him the honorary degree of LL D. In the same year, he revisited the scenes of his youth, and delighted the old parishioners of his father by recollecting them individually, while they were no less proud that their parish had produced a man who was held in such estimation in the world. During this year, also, he was married to Miss Burnet, from Aberdeenshire, the amiable niece of the distinguished professor Black, of Edinburgh. In order to render his lectures more useful to his pupils, Dr. Ferguson, about this time, published "his in stitute or synopsis of his lectures."

Dr Ferguson continued to enjoy the literary society of Edinburgh, interrupted only by the recreation of cultivating a small farm in the neighbourhood of the city, until the year 1773; when he was induced by the liberal offers of lord Chesterfield, nephew to the celebrated earl, to accompany him in his travels. After a tour through most of the countries of Europe, Dr Ferguson returned in 1775, to the duties of his chair, which, during his absence, had been ably performed by the well known Dugald Stewart. This relief from his academical duties, proved not only highly advantageous to Dr Ferguson in a pecuniary: point of view, but contributed considerably to his improvement. His lectures on his return were not only numerously attended by the usual routine of students, but by men of the first rank and talents in the country. We have the testimony of one, who, although young at the time, seems to have been well able to appreciate his talents, as to Dr Ferguson’s manner as a lecturer.—"The doctor’s mode of communicating knowledge, was firm, manly, and impressive, but mild and elegant; he was mild, but justly severe in his rebukes to the inattentive and negligent. One day that he was engaged in that part of his course that treated of the practical application of the moral qualities which he had before described, and was speaking of the folly of idleness and inattention to the business in hand, some thoughtless young men were whispering and trifling in the gallery. ‘Gentlemen,’ said he, ‘please to attend, this subject peculiarly concerns you.’" In the year 1776, Dr Ferguson answered Dr Price’s production on civil and religious liberty. The ground on which he differed with Dr Price, was on the applicability of his doctrine to society and to imperfect man.

We have an early notice of Dr Ferguson’s being engaged in the composition of his History of the Roman Republic in the following valuable letter, addressed by him to Edward Gibbon, dated Edinburgh, 18th April, 1776:—"Dear sir, I should make some apology for not writing you sooner, an answer to your obliging letter; but if you should honour me frequently with such requests, you will find that, with very good intentions, I am a very dilatory and irregular correspondent. I am sorry to tell you, that our respectable friend, Mr Hume, is still declining in his health; he is greatly emaciated, and loses strength. He talks familiarly of his near prospect of dying. His mother, it seems, died under the same symptoms; and it appears so little necessary, or proper, to flatter him, that no one attempts it. I never observed his understanding more clear, or his humour more pleasant or lively. He has a great aversion to leaving the tranquillity of his own house, to go in search of health among inns and hostlers. And his friends here gave way to him for some time; but now think it necessary that he should make an effort to try what change of place and air, or anything else Sir John Pringle may advise, can do for him. I left him this morning in the mind to comply in this article, and I hope, that he will be prevailed on to set out in a few days. He is just now sixty-five.

"I am very glad that the pleasure you give us, recoils a little on yourself, through our feeble testimony. I have, as you suppose, been employed, at any intervals of leisure or rest I have had for some years, in taking notes or collecting materials for a history of the destruction that broke down the Roman republic, and ended in the establishment of Augustus and his immediate successors. The compliment you are pleased to pay, I cannot accept of, even to my subject. Your subject now appears with advantages it was not supposed to have had, and I suspect, that the magnificence of the mouldering ruin will appear more striking, than the same building, when the view is perplexed with scaffolding, workmen, and disorderly lodgers, and the ear is stunned with the noise of destructions and repairs, and the alarms of fire. The night which you begin to describe is solemn, and there are gleams of light superior to what is to be found in any other time. I comfort myself, that as my trade is the study of human nature, I could not fix on a more interesting corner of it, than the end of the Roman republic. Whether my compilations should ever deserve the attention of any one besides myself, must remain to be determined after they are farther advanced. I take the liberty to trouble you with the enclosed for Mr Smith, (Dr Adam Smith,) whose uncertain stay in London makes me at a loss how to direct for him. You have both such reason to be pleased with the world just now, that I hope you are pleased with each other. I am, with the greatest respect, dear sir, your most obedient and humble servant, ADAM FERGUSON." This letter is not only valuable from its intrinsic worth and the reference it has to the composition of the History of the Roman Republic, but from its presenting, connected by one link, four of the greatest names in British literature. Mr Ferguson, however, was interrupted in the prosecution of his historical labours, having been, through the influence of his friend Mr Dundas, afterwards lord Melville, appointed secretary to the commissioners sent out to America in the year 1778, to negotiate an arrangement with our revolted colonies in that continent. The following historical detail will show the success of this mission:—"In the beginning of June, 1778, the new commissioners arrived at Philadelphia, more than a month after the ratification of the treaty with France had been formally exchanged. The reception they met with was such as men the most opposite in their politics had foreseen and foretold. Dr Ferguson, secretary to the commission, was refused a passport to the Congress, and they were compelled to forward their papers by the common means.

"The commissioners, at the very outset, made concessions far greater than the Americans, in their several petitions to the king, had requested or desired—greater, indeed, than the powers conferred upon them by the act seemed to authorize. Amongst the most remarkable of these, was the engagement to agree that no military force should be kept up in the different states of America, without the consent of the general congress of the several assemblies—to concur in measures calculated to discharge the debts of America, and to raise the credit and value of the paper circulation—to admit of representatives from the several states, who should have a seat and voice in the parliament of Great Britain—to establish a freedom of legislation and internal government, comprehending every privilege short of a total separation of interest, or consistent with that union of force in which the safety of the common religion and liberty depends.

"These papers, when laid before the Congress, were read with astonishment and regret, but from the declaration of INDEPENDENCE, they had neither the will, nor the power to recede. An answer, therefore, brief but conclusive, was returned by the president, Henry Laurens, declaring, ‘that nothing but an earnest desire to spare the farther effusion of human blood could have induced them to read a paper containing expressions so disrespectful to his most christian majesty, their ally, or to consider of propositions so derogatory to the honour of an independent nation. The commission under which they act, supposes the people of America to be still subject to the crown of Great Britain, which is an idea utterly inadmissible.’ The president added, ‘that he was directed to inform their excellencies of the inclination of the congress to peace, notwithstanding the unjust claims from which this war originated, and the savage manner in which it had been conducted. They will, therefore, be ready to enter upon the consideration of a treaty of peace and commerce, not inconsistent with treaties already subsisting, when the king of Great Britain shall demonstrate a sincere disposition for that purpose; and the only solid proof of this disposition, will be an explicit acknowledgment of the independence of the United States, or the withdrawing his fleets and armies.’" Conduct so haughty on the part of the Americans, necessarily put a stop to all farther negotiation, and the commissioners having, in a valedictory manifesto, appealed to the people, returned home.

On his return to Scotland, Dr Ferguson resumed the charge of his class and continued the preparation of the Roman History. That work made its appearance in the year 1783; and two years afterwards, he resigned the chair of moral philosophy in favour of Mr Dugald Stewart; while he was himself permitted to retire on the salary of the mathematical class which Mr Stewart had held. Dr Ferguson then took up his residence at Manor, in the county of Peebles, where he passed his time in literary ease and in farming; an occupation for which he had a peculiar taste, but which he ultimately found so unprofitable, that he was glad to relinquish it. He seems also to have devoted his attention to the correction of his lectures, which he published in 1793.

While exempt from all cares and in the enjoyment of good health, and of a competent fortune, Dr Ferguson, in his old age, conceived the extraordinary project of visiting Rome. He accordingly repaired once more to the continent, visiting the cities of Berlin and Vienna, where he was received with great attention. His progress southward was, however, stopped by the convulsions consequent on the French revolution. To this great political phenomenon, Dr Ferguson’s attention had been earnestly directed, and it is curious to know, that he had drawn up (although he did not publish it) a memorial, pointing out the dangers to which the liberties of Europe were exposed, and proposing a congress with objects similar to those which occupied the congress of Vienna, in 1814.

In his person, Dr Ferguson was well formed, active, and muscular; his complexion fair, his eyes blue, his features handsome, intelligent, and thoughtful. There is a very fine and correct portrait of him in an ante-room at Brompton Grove, the seat of Sir John Macpherson. Unlike many who have devoted themselves to the abstruse study of philosophy, he had an intimate knowledge of the world; having mixed much with courtiers, statesmen, politicians, and the learned and accomplished, not only in Great Britain, but throughout Europe. His knowledge of the human character was consequently accurate and extensive; his manners were polished, simple, and unostentatious; while his conversation was agreeable and instructive. Warned by an illness with which he was seized when about the age of fifty, resembling in its character an apoplectic fit, he abstained from the use of wine, and during the remainder of his life, lived most abstemiously, and enjoyed an uninterrupted course of good health. His fortune was affluent; besides the fees and salaries of his class and the price of his works, he held two pensions, one from government of £400, and another from lord Chesterfield of 200 a year. By these means, aided by a munificent gift from his pupil, Sir John Macpherson, he was enabled to purchase a small estate near St Andrews; he was also possessed of a house and garden in that city, on which he expended a thousand pounds.

Bred in the tenets of the church of Scotland, he was a respectful believer in the truths of revelation; he did not, however, conceive himself excluded from cultivating the acquaintance of those who were directly opposed to him in their religious opinions, and his intimate friendship with David Hume subjected him to the reprehension of many of the Christian professors of his time. A list of those with whom Dr Ferguson maintained an intimate acquaintance and intercourse, would include all who rose to eminence during the last half of the 18th, and the early part of the present century. Dr Ferguson left six children; three sons, and three daughters: Adam, in the army, John, in the navy, and the third son in the East India Company’s service.*