Thomas, a learned and respectable prelate of the Church of England, was born in 1693, at a village called Sibthorn, in the vale of Belvoir, in Nottinghamshire. His father was a Protestant dissenter, a pious, virtuous, and sensible man, who, having a small paternal fortune, followed no profession. His mother was the daughter of Mr Brough, a substantial gentleman farmer of Shelton, in the same county. He received his education at several private schools and academies in the country, being obliged, by various accidents, to change frequently his masters.

Notwithstanding this disadvantage, he had at the age of nineteen not only made considerable progress in Greek and Latin, and read the best writers in both languages, but had acquired a knowledge of French, Hebrew, Chaldaic, and Syriac, had learned geography, logic, algebra, geometry, conic sections, and gone through a course of lectures on Jewish antiquities and other points, preparatory to the critical study of the Bible. He had been destined by his father for orders amongst the dissenters. With this view, during the latter years of his education, his studies were chiefly turned towards divinity, in which he had made such advances, that by the time he was twenty-three he had carefully read a great part of the Scriptures, particularly the New Testament, in the original, and the best comments upon it; Eusebius's Ecclesiastical History, the Apostolical Fathers, Whiston's Primitive Christianity, and the principal writers for and against ministerial and lay conformity. But though the result of these inquiries was a well-grounded belief of the Christian revelation, yet not being at that time able to decide on some abstruse speculative doctrines, nor to determine absolutely what communion he should embrace, he resolved, like a wise and honest man, to pursue some profession, which should leave him at liberty to weigh those things more maturely in his thoughts, and not oblige him to declare or teach publicly opinions which were not yet thoroughly settled in his own mind.

In 1716, therefore, he applied himself to the study of physic, and after gaining all the medical knowledge he could, by reading the usual preparatory books, and attending the best lectures during that and the following winter in London, in order to improve himself farther, he went to Paris in January 1719. There he lodged in the same house with the celebrated anatomist Mr Winslow, whose lectures he attended, as he did those of the materia medica, chemistry, and botany, at the King's Gardens. He saw the operations of surgery at the Hôtel Dieu, and attended also for some time M. Gregoire the accoucheur, but without any design of ever practising that or any other branch of surgery. Here he became acquainted with Mr Martin Benson, afterwards bishop of Gloucester, one of the most agreeable and virtuous men of his time, with whom he quickly became connected, and not many years afterwards was united by the strictest bonds of affinity as well as affection.

During the whole of Mr Seeker's continuance at Paris, he kept up a constant correspondence with Mr Joseph Butler, afterwards bishop of Durham, with whom he became acquainted at the academy of Mr Jones, which was kept first at Gloucester, and afterwards at Tewkesbury. Mr Butler having been appointed preacher at the Rolls on the recommendation of Dr Clarke, and of Mr Edward Talbot, son of Bishop Talbot, he now took occasion to mention his friend Mr Seeker, without Seeker's knowledge, to Mr Talbot, who promised, in case he chose to take orders in the Church of England, to engage the bishop his father to provide for him. This was communicated to Mr Seeker in a letter from Mr Butler about the beginning of May 1720. He had not at that time come to any resolution of quitting the study of physic; but he began to foresee many obstacles to his pursuing that profession; and having never discontinued his application to theology, his former difficulties with regard to conformity and some other doubtful points had gradually lessened, as his judgment became stronger and his reading and knowledge more extensive. It appears also from two of his letters still extant, written from Paris to a friend in England, both of them prior to the date of Mr Butler's letter above mentioned, that he was greatly dissatisfied with the divisions and disturbances which at that particular period prevailed among the dissenters.

In this state of mind Mr Butler's unexpected proposal found him; and he was therefore very well disposed to take it into consideration. After deliberating on the subject of such a change for upwards of two months, he resolved at length to embrace the offer, and for that purpose quitted France about the beginning of August 1720.

On his arrival in England, he was introduced to Mr Talbot, with whom he cultivated a close acquaintance; but it was unfortunately of very short duration; for in the month of December that gentleman died of the small-pox. This was a great shock to all his friends, who had just conceived the highest expectations of him, but especially to an amiable lady whom he had lately married, and who was very near sinking under so sudden and grievous a stroke. Mr Seeker, besides sharing largely in the common grief, had peculiar reason to lament an accident that seemed to put an end to all his hopes; but he had taken his resolution, and he determined to persevere. It was some encouragement to him to find that Mr Talbot had, on his death-bed, recommended him, together with Mr Benson and Mr Butler, to his father's notice. Thus did that excellent young man, for he was but twenty-nine when he died, by his nice discernment of character and his considerate good nature, provide most effectually for the welfare of that church from which he himself was so prematurely snatched away; and at the same time raised up, when he least thought of it, the truest friend and protector to his wife and unborn daughter, who afterwards found in Mr Seeker all tender care and assistance which they could have hoped for from the nearest relation.

It being judged necessary by Mr Seeker's friends that he should have a degree at Oxford, and having been informed, that if he should previously take the degree of doctor of physic at Leyden, it would probably help him in obtaining the other, he went and took his degree there in March 1721; and, as part of his exercise for it, he composed and printed a dissertation De Medicina Statica, which is still extant, and is thought by the gentlemen of that profession to be a sensible and learned performance. In April the same year, he entered himself a gentleman commoner of Exeter College, Oxford; after which he obtained the degree of bachelor of arts, in consequence of the chancellor's recommendatory letter to the convocation.

He now spent a considerable part of his time in London, where he quickly gained the esteem of some of the most learned and ingenious men of those days, particularly of Dr Clarke, rector of St James's, and the celebrated Dean Berkeley, afterwards bishop of Cloyne, with whom he every day became more delighted and more closely connected. He paid frequent visits of gratitude and friendship to Mrs Talbot, widow of Mr Edward Talbot, by whom she had a daughter five months after his decease. With her lived Mrs Catherine Benson, sister of Bishop Benson, whom in many respects she greatly resembled. She had been for several years Mrs Talbot's inseparable companion, and was of unspeakable service to her at the time of her husband's death, by exerting all her courage, activity, and good sense, of which she possessed a large share, to support her friend under so great an affliction, and by afterwards attending her sickly infant with the utmost care and tenderness.

Bishop Talbot being in 1721 appointed to the see of Durham, Mr Secker was in 1722 ordained deacon by him in St James's church, and not long afterwards priest in the same place, where he preached his first sermon on 28th of March 1723. The bishop's domestic chaplain was at that time Dr Rundle, a man of warm fancy and very brilliant conversation, but apt sometimes to be carried, by the vivacity of his wit, into indiscreet and ludicrous expressions, which created him enemies, and, upon one occasion, produced disagreeable consequences. With him Mr Secker was soon afterwards associated in the bishop's family, and both were taken down by his lordship to Durham in July 1723.

In the following year the bishop gave Mr Secker the rectory of Houghton-le-Spring. This preferment putting it in his power to fix himself in the world in a manner agreeable to his inclinations, he soon afterwards made a proposal of marriage to Mrs Benson, which being accepted, they were married by Bishop Talbot in 1725. At the earnest request of both, Mrs Talbot and her daughter consented to live with them, and the two families from that time became one.

About this time Bishop Talbot also gave preferments to Mr Butler and Mr Benson, whose rise and progress in the church are here interwoven with the history of Mr Secker. In the winter of 1725-26, Mr Butler first published his incomparable sermons; of which, as Dr Beilby Porteous and Dr Stinton inform us, Mr Secker took pains to render the style more familiar, and the author's meaning more obvious; yet they were by many called obscure. Mr Secker gave his friend the same assistance in that noble work the Analogy of Religion Natural and Revealed.

He now gave up all the time he possibly could to his residence at Houghton, applying himself with alacrity to all the duties of a country clergyman, and supporting an useful and respectable character throughout. Here he would have been content to live and die; here, as he has often been heard to declare, he spent some of the happiest hours of his life; and it was no thought or choice of his own that removed him to a higher and more conspicuous situation. But Mrs Secker's health, which now began to decline, and was thought to be injured by the dampness of the situation, obliged him to think of exchanging it for a more healthy one. Accordingly, an exchange was made through the friendly interposition of Mr Benson, with Dr Finney, prebendary of Durham, and rector of Ryton; and Mr Secker was instituted to Ryton and the prebend on the 3rd of June 1727. For the two following years he lived chiefly at Durham, going every week to officiate at Ryton, and spending there two or three months together in the summer.

In July 1732 he was appointed chaplain to the king; for which favour he was indebted to Dr Sherlock, who having heard him preach at Bath, had conceived the highest opinion of his abilities, and had thought them well worthy of being brought forward into public notice. From that time an intimacy commenced between them, and he received from that great prelate many solid proofs of esteem and friendship.

His month of waiting at St James's happened to be August; and on Sunday the 27th of that month he preached before the queen, the king being then abroad. A few days afterwards, her majesty sent for him into her closet, and held a long conversation with him, in the course of which he took an opportunity of mentioning to her his friend Mr Butler. He also, not long after this, on Mr Talbot's being made lord chancellor, found means to have Mr Butler effectually recommended to him for his chaplain. The queen likewise appointed him clerk of her closet; and from this situation he rose, as his talents became more known, to those high dignities which he afterwards attained.

Mr Secker now began to have a public character, and to stand high in the estimation of those who were allowed to be the best judges of merit. He had already given proofs of abilities that plainly indicated the eminence to which he must one day rise as a preacher and a divine; and it was not long before an opportunity offered of placing him in an advantageous point of view. Dr Tyrwhit, who succeeded Dr Clarke as rector of St James's in 1729, found that preaching in so large a church endangered his health. Bishop Gibson, his father-in-law, therefore proposed to the crown that he should be made residentiary of St Paul's, and that Mr Secker should succeed him in the rectory. This arrangement was so acceptable to those in power, that it was entered into without any difficulty. Mr Secker was instituted rector on the 18th of May 1733; and in the beginning of July went to Oxford to take his degree of doctor of laws, not being of sufficient standing for that of divinity. On this occasion it was that he preached his celebrated Act Sermon, on the advantages and duties of academical education, which was universally allowed to be a masterpiece of sound reasoning and just composition. It was printed at the desire of the heads of houses, quickly passed through several editions, and is now to be found in the second collection of Occasional Sermons, published by himself in 1766.

It was thought that the reputation he acquired by this sermon contributed not a little towards that promotion which very soon followed its publication. For in December 1734, he received a very unexpected notice from Bishop Gibson, that the king had fixed on him for the see of Bristol. Dr Benson was about the same time appointed to the see of Gloucester, as was Dr Fleming to that of Carlisle; and the three new bishops were all consecrated together in Lambeth chapel, on the 19th of January 1734-1735, the consecration sermon being preached by Dr Thomas, afterwards bishop of Winchester.

The honours to which Dr Secker was thus raised in the prime of life did not in the least abate his diligence and attention. He drew up, for the use of his parishioners, an admirable course of Lectures on the Church Catechism, and not only read them once every week on the usual days, but also every Sunday evening, either at the church or one of the chapels belonging to it.

The sermons which he, at the same time, composed, were truly excellent and original. His faculties were now in their full vigour, and he had an audience to speak before which rendered the utmost exertion of them necessary. In 1737, he succeeded to the see of Oxford, on the promotion of Dr Potter to that of Canterbury, then vacant by the death of Archbishop Wake. In 1750, he was installed dean of St Paul's, for which he gave in exchange the rectory of St James's and his prebend of Durham. Having now more leisure both to prosecute his own studies and to encourage those of others, he gave Dr Church considerable assistance in his First and Second Vindication of the Miraculous Powers, against Mr Middleton; and he was of equal use to him in his Analysis of Lord Bolingbroke's Works. About the same time began Archdeacon Sharp's controversy with the followers of Mr Hutchinson, which was carried on to the end of the year 1755. Bishop Secker, we are told, read over all Dr Sharp's papers, amounting to three volumes octavo, and corrected and improved them throughout. But the ease which this change of situation gave him was soon disturbed by a heavy and unexpected stroke, namely, the loss of his three friends, Bishops Butler, Benson, and Berkeley, who were all cut off within the space of one year.

On the death of Archbishop Hutton, he was promoted to the see of Canterbury, and was confirmed at Bow-church, on the 21st of April 1758. He had never once throughout his whole life asked preferment for himself; nor shown any unbecoming eagerness for it; and the use he made of his newly-acquired dignity very clearly showed, that rank, and wealth, and power, had no other charms for him, than as they enlarged the sphere of his active and industrious benevolence.

For more than ten years, during which Dr Secker enjoyed the see of Canterbury, he resided constantly at his archiepiscopal house at Lambeth. A few months before his death, the dreadful pains he felt had compelled him to think of trying the Bath waters; but that design was stopped by the fatal accident which put an end to his life. His Grace had been for many years subject to the gout, which, in the latter part of his life, returned with more frequency and violence, and did not go off in a regular manner, but left the parts affected for a long time very weak, and was succeeded by pains in different parts of the body. About a year and a half before he died, after a fit of the gout, he was attacked with a pain in the arm, near the shoulder, and having continued about twelve months, a similar pain seized the upper and outer part of the opposite thigh, and the arm soon became easier.

On Saturday the 30th of July 1768, he was seized, as he sat at dinner, with a sickness at his stomach. He recovered before night; but the next evening, while his physicians were attending, and his servants raising him on his couch, he suddenly cried out that his thigh-bone was broken. The shock was so violent, that the servants perceived the couch to shake under him, and the pain so acute and unexpected, that it overcame the firmness he so remarkably possessed. He lay for some time in great agony; but when the surgeons arrived, and discovered with certainty that the bone was broken, he was perfectly resigned, and never afterwards asked a question about the event. A fever soon ensued.

On Tuesday he became lethargic, and continued so until about five o'clock on Wednesday afternoon, when he expired with great calmness, in the seventy-fifth year of his age. On examination, the thigh-bone was found to be cavious about four inches in length, and at nearly the same distance from its head. The disease took its rise from the internal part of the bone, and had so entirely destroyed its substance, that nothing remained at the part where it was broken but a portion of its outward integument; and even this had many perforations, one of which was large enough to admit two fingers, and was filled with a fungous substance arising from within the bone. There was no appearance of matter about the caries, and the surrounding parts were in a sound state. It was apparent that the torture which he underwent during the gradual corrosion of this bone must have been inexpressibly great.