In 1765, Mr Tytler returned to Edinburgh, after an absence of two years, which he always reckoned amongst the happiest and best spent of his life. On his return to his native city, his studies naturally assumed a more direct relation to the profession for which he was destined,—the law. With this object chiefly in view, he entered the university, where he began the study of civil law, under Dr Dick; and afterwards that of municipal law, under Mr Wallace. He also studied logic, under Dr Stevenson; rhetoric and belles lettres, under Dr Blair; and moral science, under Dr Fergusson. Mr Tytler, however, did not, by any means, devote his attention exclusively to these preparatory professional studies. He reserved a portion for those that belong to general knowledge. From these he selected natural philosophy and chemistry, and attended a course of each.

It will be seen, from the learned and eminent names enumerated above, that Mr Tytler was singularly fortunate in his teachers; and it will be seen, from those that follow, that he was no less fortunate, at this period of his life, in his acquaintance. Amongst these he had the happiness to reckon Henry Mackenzie, lord Abercromby, lord Craig, Mr Playfair, Dr Gregory, and Dugald Stewart. During the summer recesses of the university, Mr Tytler was in the habit of retiring to his father’s residence at Woodhouselee. The time spent here, however, was not spent in idleness. In the quiet seclusion of this delightful country residence, he resumed, and followed out with exemplary assiduity, the literary pursuits to which he was so devoted. He read extensively in the Roman classics, and in French and Italian literature. He studied deeply, besides, the ancient writers of England; and thus laid in a stock of knowledge, and acquired a delicacy of taste, which few have ever attained. Nor in this devotion to severer study, did he neglect those lighter accomplishments, which so elegantly relieve the exhaustion and fatigues of mental application. He indulged his taste for drawing and music, and always joined in the little family concerts, in which his amiable and accomplished father took singular delight.

In 1770, Mr Tytler was called to the bar; and in the spring of the succeeding year, he paid a visit to Paris, in company with Mr Kerr of Blackshiels. Shortly after this, lord Kames, with whom he had the good fortune to become acquainted in the year 1767, and who had perceived and appreciated his talents, having seen from time to time some of his little literary efforts, recommended to him to write something in the way of his profession. This recommendation, which had for its object at once the promotion of his interests, and the acquisition of literary fame, his lordship followed up, by proposing that Mr Tytler should write a supplementary volume to his Dictionary of Decisions. Inspired with confidence, and flattered by the opinion of his abilities and competency for the work, which this suggestion implied on the part of lord Kames, Mr Tytler immediately commenced the laborious undertaking, and in five years of almost unremitting toil, completed it. The work, which was executed in such a manner as to call forth not only the unqualified approbation of the eminent person who had first proposed it, but of all who were competent to judge of its merits, was published in folio, in 1778. Two years after this, in 1780, Mr Tytler was appointed conjunct professor of universal history in the college of Edinburgh with Mr Pringle; and in 1786, he became sole professor. From this period, till the year 1800, he devoted himself exclusively to the duties of his office; but in these his services were singularly efficient, surpassing far in importance, and in the benefits which they conferred on the student, what any of his predecessors had ever performed. His course of lectures was so remarkably comprehensive, that, although they were chiefly intended, in accordance with the object for which the class was instituted, for the benefit of those who were intended for the law, he yet numbered amongst his students many who were not destined for that profession. The favourable impression made by these performances, and the popularity which they acquired for Mr Tytler, induced him, in 1782, to publish, what he modestly entitled "Outlines" of his course of lectures. These were so well received, that their ingenious author felt himself called upon some time afterwards to republish them in a more extended form. This he accordingly did, in two volumes, under the title of "Elements of General History." The Elements were received with an increase of public favour, proportioned to the additional value which had been imparted to the work by its extension. It became a text book in some of the universities of Britain; and was held in equal estimation, and similarly employed, in the universities of America. The work has since passed through many editions. The reputation of a man of letters, and of extensive and varied acquirements, which Mr Tytler now deservedly enjoyed, subjected him to numerous demands for literary assistance and advice. Amongst these, was a request from Dr Gregory, then (1788) engaged in publishing the works of his father, Dr John Gregory, to prefix to these works an account of the life and writings of the latter. With this request, Mr Tytler readily complied; and he eventually discharged the trust thus confided to him, with great fidelity and discrimination, and with the tenderest and most affectionate regard for the memory which he was perpetuating.

Mr Tytler wrote pretty largely, also, for the well known periodicals, the Mirror and the Lounger. To the former of these he contributed, Nos. 17, 37, 59, and 79 ; and to the latter, Nos. 7, 9, 24, 44, 67, 70, and 79. The first of these were written with the avowed intention of giving a higher and sprightlier character to the work to which they were furnished; qualities in which he thought it deficient, although he greatly admired the talent and genius displayed in its graver papers; but he justly conceived, that a judicious admixture of a little humour, occasionally, would not be against its popularity. The circumstances in which his contributions to the Lounger were composed, afford a very remarkable instance of activity of mind and habits, of facility of expression, and felicity of imagination. They were almost all written at inns, where he happened to be detained for any length of time, in his occasional journeys from one place to another. Few men would have thought of devoting such hours to any useful purpose; but the papers of the Lounger, above enumerated, show how much may be made of them by genius and diligence.

On the institution of the Royal Society of Edinburgh in 1783, Mr Tytler became one of its constituent members; and was soon afterwards unanimously elected one of the secretaries of the literary class, in which capacity he drew up an account of the Origin and History of the Society, which was prefixed to the first volume of its Transactions. In 1788, Mr Tytler contributed to the Transactions, a biographical sketch of Robert Dundas of Arniston, lord president of the Court of Session; and in the year following, read a paper to the society on the vitrified forts in the Highlands of Scotland. The principal scope of this paper, which discovers great antiquarian knowledge and research, is to show, that, in all probability, this remarkable characteristic of the ancient Highland forts—their vitrification—was imparted to them, not during their erection, as was generally supposed, but at their destruction, which its author reasonably presumes, would be, in most, if not all cases, effected by fire. With the exception of some trifling differences of opinion in one or two points of minor importance, Mr Tytler’s essay met with the warm and unanimous approbation of the most eminent antiquarians of the day.

The next publication of this versatile and ingenious writer, was, an "Essay on the Principles of Translation," published, anonymously, in 1790. By one of those singular coincidences, which are not of unfrequent occurrence in the literary world, it happened that Dr Campbell, principal of the Marischal college, Aberdeen, had, but a short while before, published a work, entitled "Translations of the Gospel; to which was prefixed a Preliminary Dissertation on the Principles of Taste." Between many of the sentiments expressed in this dissertation, and those promulgated in Mr Tytler’s essay, there was a resemblance so strong and close, that Dr Campbell, on perusing the latter, immediately conceived that the anonymous author had pillaged his dissertation; and instantly wrote to Mr Creech of Edinburgh, his publisher, intimating his suspicions. Mr Tytler, however, now came forward, acknowledged himself to be the author of the suspected essay, and, in a correspondence which he opened with Dr Campbell, not only convinced him that the similarity of sentiment which appeared in their respective publications, was the result of mere accident, but succeeded in obtaining the esteem and warmest friendship of his learned correspondent.

Mr Tytler’s essay attained a rapid and extraordinary celebrity. Complimentary letters flowed in upon its author from many of the most eminent men in England; and the book itself speedily came to be considered a standard work in English criticism. Mr Tytler had now attained nearly the highest pinnacle of literary repute. His name was widely known, and was in every case associated with esteem for his worth, and admiration of his talents. It is no matter for wonder then, that such a man should have attracted the notice of those in power, nor that they should have thought it would reflect credit on themselves, to promote his interests.

In 1790, Mr Tytler, through the influence of lord Melville, was appointed to the high dignity of judge-advocate of Scotland. The duties of this important office had always been, previously to Mr Tytler’s nomination, discharged by deputy; but neither the activity of his body and mind, nor the strong sense of the duty he owed to the public, would permit him to have recourse to such a subterfuge. He resolved to discharge the duties now imposed upon him in person, and continued to do so, attending himself on every trial, so long as he held the appointment. He also drew up, while acting as judge-advocate, a treatise on Martial Law, which has been found of great utility. Of the zeal with which Mr Tytler discharged the duties of his office, and of the anxiety and impartiality with which he watched over and directed the course of justice, a remarkable instance is afforded in the case of a court-martial, which was held at Ayr. Mr Tytler thought the sentence of that court unjust; and under this impression, which was well founded, immediately represented the matter to Sir Charles Morgan, judge-advocate general of England, and prayed for a reversion of the sentence. Sir Charles cordially concurred in opinion with Mr Tytler regarding the decision of the court-martial, and immediately procured the desired reversion. In the fulness of his feelings, the feelings of a generous and upright mind, Mr Tytler recorded his satisfaction with the event, on the back of the letter which announced it.

In the year 1792, Mr Tytler lost his father, and by his death succeeded to the estate of Woodhouselee, and shortly after Mrs Tytler succeeded in a similar manner to the estate of Balmain in Inverness-shire. On taking possession of Woodhouselee, Mr Tytler designed, and erected a little monument to the memory of his father, on which was an appropriate Latin inscription, in a part of the grounds which his parents had delighted to frequent.

This tribute of filial affection paid, Mr Tytler, now in possession of affluence, and every other blessing on which human felicity depends, began to realize certain projects for the improvement and embellishment of his estate, which he had long fondly entertained, and thinking with Pope that "to enjoy, is to obey," he prepared to make the proper use of the wealth which had been apportioned to him. This was in opening up sources of rational and innocent enjoyment for himself, and in promoting the happiness and comfort of those around him. From this period he resided constantly at Woodhouselee, the mansion-house of which he enlarged in order that he might enlarge the bounds of his hospitality. The felicity, however, which he now enjoyed, and for which, perhaps, no man was ever more sincerely or piously grateful, was destined soon to meet with a serious interruption. In three years after his accession to his paternal estate, viz, in 1795, Mr Tytler was seized with a dangerous and long protracted fever, accompanied by delirium. The skill and assiduity of his friend Dr Gregory, averted any fatal consequences from the fever, but during the paroxysms of the disease he had burst a blood vessel, an accident which rendered his entire recovery at first doubtful, and afterwards exceedingly tardy. During the hours of convalescence which succeeded his illness on this occasion, Mr Tytler employed himself in improving, and adapting to the advanced state of knowledge, Derham’s Physico-Theology, a work which he had always held in high estimation. To this new edition of Derham’s work, which he published in 1799, he prefixed a "Dissertation on Final Causes." In the same year Mr Tytler wrote a pamphlet entitled, "Ireland profiting by Example, or the Question considered, Whether Scotland has gained or lost by the Union." He was induced to this undertaking by the circumstance of the question having been then furiously agitated, whether any benefit had arisen, or was likely to arise from the Union with Ireland. Of Mr Tytler’s pamphlet the interest was so great that no less than 3000 copies were sold on the day of publication.

The well earned reputation of Mr Tytler still kept him in the public eye, and in the way of preferment. In 1801, a vacancy having occurred in the bench of the court of Session by the death of lord Stonefield, the subject of this memoir was appointed, through the influence of lord Melville, to succeed him, and took his seat, on the 2nd of February, 1802, as lord Woodhouselee. His lordship now devoted himself to the duties of his office with the same zeal and assiduity which had distinguished his proceedings as judge-advocate. While the courts were sitting, he resided in town, and appropriated every hour to the business allotted to him; but during the summer recess, he retired to his country-seat, and there devoted himself with similar assiduity to literary pursuits. At this period his lordship contemplated several literary works; the gratitude, and a warm and affectionate regard for the memory of his early patron induced him to abandon them all, in order to write the Life of Lord Kames. This work, which occupied him, interveniently, for four years, was published in 2 volumes, quarto, in 1807, with the title of "Memoirs of the Life and Writings of Henry Home, lord Kames." Besides a luminous account of its proper subject, and of all his writings, it contains a vast fund of literary anecdote, many notices of eminent persons, of whom there was hardly any other commemoration.

On the elevation of lord justice clerk Hope to the president’s chair in 1811, lord Woodhouselee was appointed to the Justiciary bench, and with this appointment terminated his professional advancement. His lordship still continued to devote his leisure hours to literary pursuits, but these were now exclusively confined to the revision of his Lectures upon History. In this task, however, he laboured with unwearied assiduity, adding to them the fresh matter with which subsequent study and experience had supplied him, and improving them where an increased refinement in taste showed him they were defective.

In 1812, lord Woodhouselee succeeded to some property bequeathed him by his friend and relation, Sir James Craig, governor of Canada. On this occasion a journey to London was necessary, and his lordship accordingly proceeded thither. Amongst the other duties which devolved upon him there, as nearest relative of the deceased knight, was that of returning to the sovereign the insignia of the order of the Bath with which Sir James had been invested. In the discharge of this duty his lordship had an interview with the Prince Regent, who received him with marked cordiality, and, from the conversation which afterwards followed, became so favourably impressed regarding him, that he caused an intimation to be conveyed to him soon after, that the dignity of baronet would be conferred upon him if he chose it. This honour, however, his lordship modestly declined.

On his return from London, his lordship, who was now in the sixty-fifth year of his age, was attacked with his old complaint, and so seriously, that he was advised, and prevailed upon to remove from Woodhouselee to Edinburgh for the benefit of the medical skill which the city afforded. No human aid, however, could now avail him. His complaint daily gained ground in despite of every effort to arrest its progress. Feeling that he had not long to live, although perhaps, not aware that the period was to be so brief, he desired his coachman to drive him out on the road in the direction of Woodhouselee, the scene of the greater portion of the happiness which he had enjoyed through life, that he might obtain a last sight of his beloved retreat.

On coming within view of the well-known grounds his eyes beamed with a momentary feeling of delight. He returned home, ascended the stairs which led to his study with unwonted vigour, gained the apartment, sank on the floor, and expired without a groan.