Having completed the customary course of education at this seminary, he was entered as a student at the college of Edinburgh. Under the immediate instruction of such a mathematician and teacher as his father, it may readily be supposed that he made early proficiency in the exact sciences; but the distinguishing bent of his philosophical genius recommended him in a still more particular manner to the notice of Dr Stevenson, then professor of logic, and of Dr Adam Ferguson, who filled the moral philosophy chair.

In order to prosecute his favourite studies under the most favourable circumstances, he proceeded, at the commencement of the session of 1771, to the university of Glasgow, to attend the lectures of Dr Reid, who was then in the zenith of his reputation. The progress which he here made in his metaphysical studies, was proportioned to the ardour with which he devoted himself to the subject; and, not content with listening merely to the instructions of his master, or with the speculations of his leisure hours, he composed during the session that admirable Essay on Dreaming, which he afterwards published in the first volume of the "Philosophy of the Human Mind."

The declining state of his father’s health compelled him, in the autumn of the following year, before he had reached the age of nineteen, to undertake the task of teaching the mathematical classes in the Edinburgh university. With what success he was able to fulfill this duty, was sufficiently evinced by the event; for, with all Dr Matthew Stewart’s well-merited celebrity, the number of students considerably increased under his son. As soon as he had completed his twenty-first year, he was appointed assistant and successor to his father, and in this capacity he continued to conduct the mathematical studies in the university till his father’s death, in the year 1785, when he was nominated to the vacant chair.

Although this continued, however, to be his ostensible situation in the university, his avocations were more varied. In the year 1778, during which Dr Adam Ferguson accompanied the commissioners to America, he undertook to supply his place in the moral philosophy class; a labour that was the more overwhelming, as he had for the first time given notice, a short time before his assistance was requested, of his intention to add a course of lectures on astronomy to the two classes which he taught as professor of mathematics. Such was the extraordinary fertility of his mind, and the facility with which it adapted its powers to such inquiries, that, although the proposal was made to him and accepted on Thursday, he commenced the course of metaphysics the following Monday, and continued, during the whole of the season, to think out and arrange in his head in the morning, (while walking backwards and forwards in a small garden attached to his father’s house in the college,) the matter of the lecture of the day. The ideas with which he had thus stored his mind, he poured forth extempore in the course of the forenoon, with an eloquence and a felicity of illustration surpassing in energy and vivacity (as those who have heard him have remarked) the more logical and better digested expositions of his philosophical views, which he used to deliver in his maturer years. The difficulty of speaking for an hour extempore every day on a new subject for five or six months, is not small; but, when superadded to the mental exertion of teaching also daily, two classes of mathematics, and of delivering, for the first time, a course of lectures on astronomy, it may justly be considered as a very singular instance of intellectual vigour. To this season he always referred as the most laborious of his life; and such was the exhaustion of the body, from the intense and continued stretch of the mind, that, on his departure for London, at the close of the academical session, it was necessary to lift him into the carriage.

In the year 1780, he began to receive some young noblemen and gentlemen into his house as pupils, under his immediate superintendence, among whom were to be numbered the late lord Belhaven, the late marquis of Lothian, Basil lord Daer, [Burns’ first interview with Mr Stewart, in the presence of this amiable young nobleman, at Catrine, will be in every reader’s remembrance, as well as the philosopher’s attention to the poet during his subsequent residence in Edinburgh. The house occupied by Mr Stewart at Catrine still exists, a small narrow old fashioned building, detached from the village.] the late lord Powerscourt, Mr Muir Mackenzie of Delvin, and the late Mr Henry Glassford. In the summer of 1783, he visited the continent for the first time, having accompanied the late marquis of Lothian to Paris; on his return from whence, in the autumn of the same year, he married Helen Bannatyne, daughter of Neil Bannatyne, Esq., a merchant in Glasgow.

In the year 1785, during which Dr Matthew Stewart’s death occurred, the health of Dr Ferguson rendered it expedient for him to discontinue his official labours in the university, and he accordingly effected an exchange of offices with Mr Stewart, who was transferred to the class of moral philosophy, while Dr Ferguson retired on the salary of mathematical professor. In the year 1787, Mr Stewart was deprived of his wife by death; and, the following summer, he again visited the continent, in company with the late Mr Ramsay of Barnton.

These slight indications of the progress of the ordinary occurrences of human life, must suffice to convey to the reader an idea of the connexion of events, up to the period when Mr Stewart entered on that sphere of action in which he laid the foundation of the great reputation which he acquired as a moralist and a metaphysician. His writings are before the world, and from them posterity may be safely left to form an estimate of the excellence of his style of composition--of the extent and variety of his learning and scientific attainments—of the singular cultivation and refinement of his mind—of the purity and elegance of his taste--of his warm relish for moral and for natural beauty—of his enlightened benevolence to all mankind, and of the generous ardour with which he devoted himself to the improvement of the human species--of all of which, while the English language endures, his works will continue to preserve the indelible evidence. But of one part of his fame no memorial will remain but in the recollection of those who have witnessed his exertions. As a public speaker, he was justly entitled to rank among the very first of his day; and, had an adequate sphere been afforded for the display of his oratorical powers, his merit in this line alone would have sufficed to secure him a lasting reputation. Among those who attracted the highest admiration in the senate and at the bar, there were not a few who could bear testimony to his extraordinary eloquence. The ease, the grace, and the dignity of his action; the compass and harmony of his voice, its flexibility and variety of intonation; the truth with which its modulation responded to the impulse of his feelings, and the sympathetic emotions of his audience; the clear and perspicuous arrangement of his matter; the swelling and uninterrupted flow of his periods, and the rich stores of ornament which he used to borrow from the literature of Greece and of Rome, of France and of England, and to interweave with his spoken thoughts with the most apposite application, were perfections not possessed in a superior degree by any of the most celebrated orators of the age. His own opinions were maintained without any overweening partiality; his eloquence came so warm from the heart, was rendered so impressive by the evidence which it bore of the love of truth, and was so free from all controversial acrimony, that what has been remarked of the purity of purpose which inspired the speeches of Brutus, might justly be applied to all that he spoke and wrote; for he seemed only to wish, without further reference to others than a candid discrimination of their errors rendered necessary, simply and ingenuously to disclose to the world the conclusions to which his reason had led him: "Non malignitate ant invidia, sed simpliciter et ingenue, judicium animi sui detexisse."

In 1790, after being three years a widower, he married Helen D’Arcy Cranstoun, a daughter of the honourable Mr George Cranstoun, a union to which he owed much of the subsequent happiness of his life. About this time it would appear to have been that he first began to arrange some of his metaphysical papers with a view to publication. At what period he deliberately set himself to think systematically on these subjects is uncertain. That his mind had been habituated to such reflections from a very early period is sufficiently known. He frequently alluded to the speculations that occupied his boyish, and even his infant thoughts, and the success of his logical and metaphysical studies at Edinburgh, and the Essay on Dreaming, which forms the fifth section of the first part of the fifth chapter of the first volume of the Philosophy of the Human Mind, composed while a student at the college of Glasgow in 1772, at the age of eighteen, are proofs of the strong natural bias which he possessed for such pursuits. It is probable, however, that he did not follow out the inquiry as a train of thought, or commit many of his ideas to writing before his appointment in 1785, to the professorship of moral philosophy, gave a necessary and steady direction to his investigation of metaphysical truth. In the year 1792, he first appeared before the public as an author, at which time the first volume of the Philosophy of the Human Mind was given to the world. While engaged in this work he had contracted the obligation of writing the life of Adam Smith, the author of the Wealth of Nations, and very soon after he had disembarrassed himself of his own labours, he fulfilled the task which he had undertaken; the biographical memoir of this eminent man having been read at two several meetings of the Royal Society of Edinburgh, in the months of January and March, 1793. In the course of this year also, he published the Outlines of Moral Philosophy; a work which he used as a text book, and which contained brief notices, for the use of his students, of the subjects which formed the matter of his academical prelections. In March, 1796, he read before the Royal Society his account of the Life and Writings of Dr Robertson, and in 1802, that of the Life and Writings of Dr Reid.

By these publications alone, which were subsequently combined in one volume, quarto, he continued to be known as an author till the appearance of his volume of Philosophical Essays in 1810; a work to which a melancholy interest attaches, in the estimation of his friends, from the knowledge that it was in the devotion of his mind to this occupation that he sought a diversion to his thoughts, from the affliction he experienced in the death of his second and youngest son. Although, however, the fruits of his studies were not given to the world, the process of intellectual exertion was unremitted. The leading branches of metaphysics had become so familiar to his mind, that the lectures which he delivered, very generally extempore, and which varied more or less in the language and matter every year, seemed to cost him little effort, and he was thus left in a great degree at liberty to apply the larger part of his day to the prosecution of his further speculations. Although he had read more than most of those who are considered learned, his life, as he has himself somewhere remarked, was spent much more in reflecting than in reading; and so unceasing was the activity of his mind, and so strong his disposition to trace all subjects of speculation, that were worthy to attract his interest, up to their first principles, that all important objects and occurrences furnished fresh matter to his thoughts. The public events of the time suggested many of his inquiries into the principles of political economy; his reflections on his occasional tours through the country, many of his speculations on the picturesque, the beautiful, and the sublime; and the study of the characters of his friends and acquaintances, and of remarkable individuals with whom he happened to be thrown into contact, many of his most profound observations on the sources of the varieties and anomalies of human nature.

In the period which intervened between the publication of his first volume of the Philosophy of the Human Mind, and the appearance of his Philosophical Essays, he produced and prepared the matter of all his other writings, with the exception of his Dissertation on the Progress of Metaphysical and Ethical Philosophy, prefixed to the Supplement of the Encyclopedia Britannica. Independent of the prosecution of those metaphysical inquiries which constitute the substance of his second and third volumes of the Philosophy of the Human Mind, to this epoch of his life are to be referred the speculations in which he engaged with respect to the science of political economy, the principles of which he first embodied in a course of lectures, which, in the year 1800, he added as a second course to the lectures which formed the immediate subject of the instruction previously delivered in the university from the moral philosophy chair. So general and extensive was his acquaintance with almost every department of literature, and so readily did he arrange his ideas on any subject, with a view to their communication to others, that his colleagues frequently, in the event of illness or absence, availed themselves of his assistance in the instruction of their classes. In addition to his own academical duties, he repeatedly supplied the place of Dr John Robison, professor of natural philosophy. He taught for several months during one winter the Greek classes for the late Mr Dalzell: he more than one season taught the mathematical classes for Mr Playfair: he delivered some lectures on logic during an illness of Dr Finlayson; and, if we mistake not, he one winter lectured for some time on belles lettres for the successor of Dr Blair.

In I 796, he was induced once more to open his house for the reception of pupils; and in this capacity, the late lord Ashburton, the son of the celebrated Mr Dunning, the earl of Warwick, the earl of Dudley, the present lord Palmerston, and his brother the honourable Mr Temple, were placed under his care. The present marquis of Lansdowne, though not an inmate in his family, was resident at this time in Edinburgh, and a frequent guest at his house, and for him he contracted the highest esteem; and he lived to see him, along with two of his own pupils, cabinet ministers at the same time. Justly conceiving that the formation of manners, and of taste in conversation, constituted a no less important part in the education of men destined to mix so largely in the world, than their graver pursuits, he rendered his house at this time the resort of all who were most distinguished for genius, acquirement, or elegance in Edinburgh, and of all the foreigners who were led to visit the capital of Scotland. So happily did he succeed in assorting his guests, so well did he combine the grave and the gay, the cheerfulness of youth with the wisdom of age, and amusement with the weightier topics that formed the subject of conversation to his more learned visitors, that his evening parties possessed a charm which many who frequented them have since confessed they have sought in vain in more splendid and insipid entertainments. In the year 1806, he accompanied his friend the earl of Lauderdale on his mission to Paris; and he had thus an opportunity not only of renewing many of the literary intimacies which he had formed in France before the commencement of the Revolution, but of extending his acquaintance with the eminent men of that country, with many of whom he continued to maintain a correspondence during his life.

While individuals of inferior talents, and of much inferior claims, had received the most substantial rewards for their services, it had been long felt that a philosopher like Stewart, who derived so small an income from his professional occupations, was both unjustly and ungenerously overlooked by his country. During the continuance of Mr Pitt’s administration, when the government had so much to do for those who were immediately attached to it, it was hardly perhaps to be expected that an individual who owned no party affection to it, should have participated of its favours. On the accession, however, of the Whig administration, in 1806, the oversight was corrected, though not in the manner which was to have been wished. A sinecure office, that of gazette writer for Scotland, was erected for the express purpose of rewarding Mr Stewart, who enjoyed with it a salary of 600 pounds a-year for the remainder of his life. The peculiar mode in which the reward was conveyed, excited much notice at the time. It was agreed on all hands, that Mr Stewart merited the highest recompense; but it was felt by the independent men of all parties, that a liberal pension from the crown would have expressed the national gratitude in a more elegant manner, and placed Mr Stewart’s name more conspicuously in the list of those public servants, who are repaid, in the evening of life, for the devotion of their early days to the honour and interest of their country.

The year after the death of his son, he relinquished the active duties of his chair in the university, and removed to Kinneil House, a seat belonging to the duke of Hamilton, on the banks of the Frith of Forth, about twenty miles from Edinburgh, where he spent the remainder of his days in philosophical retirement. [In 1812, Mr Stewart read, before the Royal Society of Edinburgh, a highly interesting memoir, entitled, "Some Account of a Boy born Deaf and Blind;" which was subsequently published in the Transactions of that learned body. The boy was James Mitchell, the son of a clergyman in the north of Scotland; and, owing to his unfortunate defects, his knowledge of external objects was necessarily conveyed through the organs of touch, taste, and smell, only. Mr Stewart entertained hopes of being able to ascertain, from this case, the distinction between the original and acquired perceptions of sight; an expectation, however, which, from various circumstances, was not realised.] From this place were dated, in succession, the Philosophical Essays in 1810; the second volume of the Philosophy of the Human Mind, in 1813; [ He retired from active life, upon an arrangement with the scarcely less celebrated Dr Thomas Brown, who had been his own pupil, who now agreed, as joint professor with Mr Stewart, to perform the whole duties of the chair. Mr Stewart’s biographer in the Edinburgh Encyclopaedia, gives the following paragraph, in reference to this connexion,--"Although it was on Mr Stewart’s recommendations that Dr Brown was raised to the chair of moral philosophy, yet the appointment did not prove to him a source of unmixed satisfaction. The fine poetical imagination of Dr Brown, the quickness of his apprehension, and the acuteness and ingenuity of his argument, were qualities but little suited to that patient as, continuous research, which the phenomena of the mind so peculiarly demand. He accordingly composed his lectures with the same rapidity that he would have done a poem, and chiefly from the resources of his own highly gifted, but excited mind. Difficulties which had appalled the stoutest hearts, yielded to his bold analysis; and, despising the formalities of a siege, he entered the temple of pneumatology by storm. When Mr Stewart was apprized that his own favourite and best founded opinions were controverted from the very chair which he had scarcely quitted; that the doctrines of his revered friend and master, Dr Reid, were assailed with severe, and not very respectful animadversions; and that views even of a doubtful tendency were freely expounded by his ingenious colleague, his feelings were strongly roused; and, though they were long repressed by the peculiar circumstances of his situation, yet he has given them full expression, in a note in the third volume of his Elements, which is alike remarkable for the severity and delicacy of its reproof."

It is worthy of notice, that from 1810 to 1818, when Mr Adam Ferguson died, there were alive three professors of moral philosophy, who had been, or were connected with the Edinburgh university. Upon the death of Dr Brown, in 1820, Mr Stewart resigned the chair in favour of the late Mr John Wilson, who succeeded.] the Preliminary Dissertation to the Encyclopaedia; the continuation of the second part of the Philosophy, in 1827; and, finally, in 1828, the third volume, containing the Philosophy of the Active and Moral Powers of Man; a work which he completed only a few short weeks before his career was to close for ever. Here he continued to be visited by his friends, and by most foreigners who could procure an introduction to his acquaintance, till the month of January, 1822, when a stroke of palsy, which nearly deprived him of the power of utterance, in a great measure incapacitated him for the enjoyment of any other society than that; of a few intimate friends, in whose company he felt no constraint. This great calamity, which bereaved him of the faculty of speech, of the power of exercise, of the use of his right hand,--which reduced him to a state of almost infantile dependence on those around him, and subjected him ever after to a most abstemious regimen, he bore with the most dignified fortitude and tranquillity. The malady which broke his health and constitution for the rest of his existence, happily impaired neither any of the faculties of his mind, nor the characteristic vigour and activity of his understanding, which enabled him to rise superior to the misfortune. As soon as his strength was sufficiently re-established, he continued to pursue his studies with his wonted assiduity, to prepare his works for the press with the assistance of his daughter as an amanuensis, and to avail himself with cheerful and unabated relish of all the sources of gratification which it was still within his power to enjoy, exhibiting, among some of the heaviest infirmities incident to age, an admirable example of the serene sunset of a well-spent life of classical elegance and refinement, so beautifully imagined by Cicero "Quiete, et pure, et eleganter actae aetatis, placida ac lenis senectus."

In general company, his manner bordered on reserve; but it was the comitsate condita gravitae, and belonged more to the general weight and authority of his character, than to any reluctance to take his share in the cheerful intercourse of social life. He was ever ready to acknowledge with a smile the happy sallies of wit, and no man had a keener sense of the ludicrous, or laughed more heartily at genuine humour. His deportment and expression were easy and unembarrassed, dignified, elegant, and graceful. His politeness was equally free from all affectation, and from all premeditation. It was the spontaneous result of the purity of his own taste, and of a heart warm with all the benevolent affections, and was characterized by a truth and readiness of tact that accommodated his conduct with undeviating propriety to the circumstances of the present moment, and to the relative situation of those to whom he addressed himself. From an early period of lile, he had frequented the best society both in France and in this country, and he had in a peculiar degree the air of good company. In the society of ladies he appeared to great advantage, and to women of cultivated understanding his conversation was particularly acceptable and pleasing. The immense range of his erudition, the attention he had bestowed on almost every branch of philosophy, his extensive acquaintance with every department of elegant literature, ancient or modern, and the fund of anecdote and information which he had collected in the course of his intercourse with the world, with respect to almost all the eminent men of the day, either in this country or in France, enabled him to find suitable subjects for the entertainment of the great variety of visitors of all descriptions, who at one period frequented his house. In his domestic circle, his character appeared in its most amiable light, and by his family he was beloved and venerated almost to adoration. So uniform and sustained was the tone of his manners, and so completely was it the result of the habitual influence of the natural elegance and elevation of his mind on his external demeanour, that when alone, with his wife and children, it hardly differed by a shade from that which he maintained in the company of strangers; for, although his fondness, and familiarity, and playfulness, were alike engaging and unrestrained, he never lost anything either of his grace or his dignity: "Nec vero ille in luce modo, atque in oculis civium, magnus, sed intus domique praestantior." As a writer of the English language,--as a public speaker,--as an original, a profound, and a cautious thinker,—as an expounder of truth,--as an instructor of youth,—as an elegant scholar,—as an accomplished gentleman;--in the exemplary discharge of the social duties,—in uncompromising consistency and rectitude of principle,--in unbending independence,—in the warmth and tenderness of his domestic affections,--in sincere and unostentatious piety,—in the purity and innocence of his life, few have excelled him: and, take him for all in all, it will be difficult to find a man, who, to so many of the perfections, has added so few of the imperfections, of human nature. "Mihi quidem quanquam est subito ereptus, vivit tamen, semperque vivet; virtutem enim amavi illius viri, quae extincta non est; nec mihi soli versatur ante oculos, qui illam semper in manibus habui, sed etiam posteris erit clara et insignis."

Mr Stewart’s death occurred on the 11th of June, 1828, at No. 5, Ainslie Place, Edinburgh, where he had been for a few days on a visit.

The remains of this distinguished philosopher were interred in the Canon-gate churchyard, near the honoured remains of Dr Adam Smith. At a meeting of his friends and admirers, which soon after took place, a subscription was entered into for erecting a monument, in some conspicuous situation, to his memory; and a large sum being immediately collected, the work was soon after commenced, under the superintendence of Mr Playfair, architect. Mr Stewart’s monument is an elegant Grecian temple, with a simple cinerary urn in the centre, and occupies a most fortunate situation on the south-west shoulder of the Calton hill, near the Observatory.

Mr Stewart left behind him a widow and two children, a son and daughter; the former of whom, lieutenant-colonel Matthew Stewart, has published an able pamphlet on Indian affairs. With appropriate generosity, the government allowed the sinecure enjoyed by Mr Stewart, to descend to his family.