The name of Isaac Barrow stands eminent among the divines and philosophers of the seventeenth century. Of the many good and great men whom it is the glory of Trinity College, Cambridge, to number as her foster-sons, there is none more good, none perhaps, after Bacon and Newton, more distinguished than he: and he has an especial claim to the gratitude of all members of that splendid foundation as the projector of its unequalled library, as well as a liberal benefactor in other respects.

The father of Barrow, a respectable citizen of London, was linen-draper to Charles I., and the son was naturally brought up in royalist principles. The date of his birth is variously assigned by his biographers, but the more probable account fixes it to October, 1630. It is recorded that his childhood was turbulent and quarrelsome; that he was careless of his clothes, disinclined to study, and especially addicted to fighting and promoting quarrels among his school-fellows; and of a temper altogether so unpromising, that his father often expressed a wish, that if any of his children should die, it might be his son Isaac. He was first sent to school at the Charter House, and removed thence to Felstead in Essex. Here his disposition seemed to change: he made great progress in learning, and was entered at Trinity College in 1645, in his fifteenth year, it being then usual to send boys to college about that age. He passed his term as an under graduate with much credit. The time and place were not favourable to the promotion of Royalists; for a royalist master had been ejected to make room for one placed there by the Parliament, and the fellows were chiefly of the same political persuasion. But Barrow’s good conduct and attainments won the favour of his superiors, and in 1649, the year after he took his degree, he was elected fellow. It deserves to be known, for it is honourable to both parties, that he never disguised or compromised his own principles.

His earlier studies were especially turned towards natural philosophy; and, rejecting the antiquated doctrines then taught in the schools, he selected Bacon, Galileo, and Descartes as his favourite authors. He did not commence the study of mathematics until after he had gained his fellowship, and was led to it in a very circuitous way. He was induced to read the Greek astronomers, with a view to solving the difficulties of ancient chronology; and to understand their works a thorough knowledge of geometry was indispensable. He therefore undertook the study of that science; which suited the bent of his genius so well, that he became one of the greatest proficients in it of his age. His first intention was to become a physician, and he made considerable progress in anatomy, chemistry, botany, and other sciences subservient to the profession of medicine; but he changed his mind, and determined to make divinity his chief pursuit. In 1655 he went abroad. His travels extended through France, Italy, and the Levant, to Constantinople; and, after an absence of four years, he returned to England through Germany and Holland. During this period he lost no opportunity of prosecuting his studies; and he sent home several descriptive poems, and some letters, written in Latin, which are printed in his Opuscula, in the fourth volume of the folio edition of his works. In the voyage to Smyrna he gave a proof of the high spirit, which, purified from its childish unruliness and violence, continued to form part of his character through life. The vessel being attacked by an Algerine corsair, Barrow remained on the deck, cheerfully and vigorously fighting, until the assailant sheered off. Being asked afterwards why he did not go into the hold, and leave the defence of the ship to those whom it concerned, he replied, “It concerned no one more than myself. I would rather have died than fallen into the hands of those merciless pirates.” He has described this voyage, and its eventful circumstances, in a poem contained in his Opuscula.

He entered into orders in 1659, and in the following year was made Greek Professor at Cambridge. The numerous offices to which he was appointed about this time, show that his merits were generally and highly esteemed. He was chosen to be Professor of Geometry at Gresham College in 1662; and was one of the first fellows elected into the Royal Society, after the incorporation of that body by charter in 1663; in which year he was also appointed the first mathematical lecturer on the foundation of Mr. Lucas, at Cambridge. Not that he made sinecures of these responsible employments, or thought himself qualified to discharge the duties of all at once: for he resigned the Greek professorship, on being appointed Lucasian Professor, for reasons explained in his introductory oration, which is extant in the Opuscula. The Gresham professorship he also gave up in 1664, intending thenceforth to reside at Cambridge. Finally, in 1669, he resigned the Lucasian chair to his great successor, Newton, intending to devote himself entirely to the study of divinity. Barrow received the degree of D.D. by royal mandate, in 1670; and, in 1672, was raised to the mastership of Trinity College by the King, with the compliment, “that he had given it to the best scholar in England.” In that high station he distinguished himself by liberality: he remitted several allowances which his predecessors had required from the college; he set on foot the scheme for a new library, and contributed in purse, and still more by his personal exertions, to its completion. It should be remarked that his patent of appointment being drawn up, as usual, with a permission to marry, he caused that part to be struck out, conceiving it to be at variance with the statutes. He was cut off by a fever in the prime of life, May 4, 1679, aged 49, during a visit to London. His remains were honourably deposited in Westminster Abbey, among the worthies of the land; and in that noble building a monument was erected to him by the contributions of his friends.

Of Barrow’s mathematical works we must speak briefly. The earliest of them was an edition of Euclid’s Elements, containing all the books, published at Cambridge in 1655, followed by an edition of the Data in 1657. His Lectiones OpticÆ, the first lectures delivered on the Lucasian foundation, were printed in 1669, and attracted the following commendation from the eminent mathematician, James Gregory. “Mr. Barrow, in his Optics, shows himself a most subtle geometer, so that I think him superior to any that ever I looked upon. I long exceedingly to see his geometrical lectures, especially because I have some notions on that subject by me.” In this work, (we speak on the authority of Montucla, part iv. viii.), Barrow has applied himself principally to discuss subjects unnoticed or insufficiently explained by preceding authors. Among these was the general problem, to determine the focus of a lens; which, except in a few cases, as where the opposite sides of the lens are similar, and the incident rays of light parallel to the axis, had hitherto been left to the practical skill and experience of the workman. Barrow gave a complete solution of the problem, comprised in an elegant formula which includes all cases, whether of parallel, convergent, or divergent rays. This book, says Montucla, is a mine of curious and interesting propositions in optics, to the solution of which geometry is applied with peculiar elegance.

The Lectiones GeometricÆ, full of profound researches into the metaphysics of geometry, the method of tangents, and the properties of curvilinear figures, appeared in the following year, 1670. The vast improvements in our methods of investigation, arising out of the invention of the fluxional or differential calculus, have cast into the shade the labours, and in part the fame, of the early geometricians, and have made that easy, which before was all but impossible. This work, however, is remarkable as containing a way of determining the subtangent of a curve, justly characterized by Montucla as being so intimately connected with the above-named method of analysis, that it is needless to seek in subsequent works the main principle of the differential calculus. The inquiring reader will find a full account of it in Montucla, or in Thomson’s History of the Royal Society, page 275. There is an English translation of the Lectiones GeometricÆ by Stone, published in 1735. Barrow also edited the works of Archimedes, the Conics of Apollonius, and the Spherics of Theodosius, in a very compressed form, in 1 vol. 8vo. Lond. 1675. The treatise of Archimedes on the Sphere and Cylinder, and the MathematicÆ Lectiones, a series of Lucasian lectures, read in 1664 and subsequent years, were not printed until 1683, after the author’s death. This work, or at least Kirby’s translation, published about 1734, contains the Oration which he made before the University on his election to the Lucasian chair. For further detail see Ward’s Lives of the Gresham Professors.

It is however as a theologian that Barrow is best known to the present age. Unlike his scientific writings, his theological works never can grow obsolete, for they contain eternal truths set forth with a power of argument, and force of eloquence, which must ever continue to command the admiration of those who are capable of appreciating and relishing the noblest qualities and products of the human mind. The light of revelation shone clearly and steadily then as now; no modern discoveries can increase or diminish its brightness; no new methods of reasoning, no more convenient forms of notation or expression, can supersede the sterling excellences which we have just ascribed to this great divine. Others may rise up (they are yet to come) equal or superior to him in these very excellences; still their fame can never detract from his; and Barrow with his great predecessor, Hooker, will not fail to be classed among the luminaries of the English church, and the standard authors of the English language. Copious and majestic in his style, his sermons were recommended by the great Lord Chatham to his great son, as admirably adapted to imbue the public speaker with the coveted “abundance of words” the knowledge and full command of his native language. He himself neglected not to increase his stores from the models of ancient eloquence; and his manuscripts, preserved in Trinity College Library, bear testimony to the diligence with which he transcribed the finest passages of the Greek and Latin authors, especially Demosthenes and Chrysostom. His sermons were long, too long it was thought by many of his hearers; but they were carefully composed, written and rewritten again and again, and their method, argumentative closeness, and abundant learning, show that he thought no pains too great to bestow on the important duty of public teaching. Warburton said that in reading Barrow’s sermons, he was obliged to think. They are numerous, considering their nature and the comparatively short period of the author’s clerical life. The first edition of his works, by Archbishop Tillotson, to whom, in conjunction with his friend and biographer Mr. Hill, Barrow left his manuscripts, contains seventy-seven sermons on miscellaneous subjects, of which only two were printed, and those not published, during the author’s life; together with a series of thirty-four sermons on the Apostle’s Creed. Mr. Hughes, the late editor of his works, has added to the former collection five more, printed for the first time from the original MSS. in Trinity Library. We quote from the life prefixed to that edition, the eloquent passage in which Mr. Hughes speaks of these admirable works.

“Never, probably, was religion at a lower ebb in the British dominions, than when that profligate Prince Charles II., who sat unawed on a throne formed as it were out of his father’s scaffold, found the people so wearied of puritanical hypocrisy, presbyterian mortifications, and a thousand forms of unintelligible mysticism, that they were ready to plunge into the opposite vices of scepticism or infidelity, and to regard with complacency the dissolute morals of himself and his vile associates. To denounce this wickedness in the most awful terms; to strike at guilt with fearless aim, whether exalted in high places, or lurking in obscure retreats; to delineate the native horrors and sad effects of vice, to develope the charms of virtue, and inspire a love of it in the human heart; in short, to assist in building up the fallen buttresses and broken pillars of God’s church upon earth, was the high and holy duty to which Barrow was called.”

Besides his sermons, Barrow wrote a shorter Exposition of the Creed, an Exposition of the Decalogue, an Exposition of the Lord’s Prayer, and a short account of the doctrine of the Sacraments. These were composed in 1669, the year in which the Lectiones OpticÆ were published, in obedience to some college regulation, and, Mr. Hughes conjectures, as exercises for a college preachership. Barrow says, in a letter, that they so took up his thoughts, that he could not easily apply them to any other matter. His great work on the Pope’s Supremacy was not composed till 1676. The pains which he took with it were immense; and we are told by the same authority that “the state of his MS. in Trinity Library shows that probably no piece was ever composed more studiously, digested more carefully, or supported by more numerous and powerful authorities.” Barrow states in this work the several positions, on which the Romanists ground their claim on behalf of the Bishop of Rome, for universal supremacy over the Christian church. These he divides into seven heads, which he proceeds severally and successively to refute. “This treatise,” says Dr. Tillotson, in his preface to it, “he gave to me on his death-bed, with the character that he hoped it was indifferent perfect, though not altogether as he had intended it, if God had granted him longer life. He designed indeed to have transcribed it again, and to have filled up those many spaces which were purposely left in it for the farther confirmation and illustration of several things, by more testimonies and instances which he had in his thoughts. And it would certainly have added much to the beauty and perfection of this work, had it pleased God that he had lived to finish it to his mind, and to have given it his last hand. However, as it is, it is not only a just, but an admirable discourse on this subject, which many others have handled before, but he hath exhausted it; insomuch that no argument of moment, nay, hardly any consideration properly belonging to it, hath escaped his large and comprehensive mind. He hath said enough to silence the controversy for ever, and to deter all wise men of both sides from meddling any further with it.” Appended to this treatise on the Supremacy of the Pope, is a discourse on the Unity of the Church.

We conclude with a few scattered notices of the character and person of this excellent man. His habits, it will readily be supposed, were very laborious. Dr. Pope, in his Life of Bishop Ward, says that during winter Barrow would rise before light, being never without a tinder-box, and that he has known him frequently rise after his first sleep, light and burn out his candle, and then return to bed before day. In pecuniary affairs he was generous in the extreme. Of his liberality to his college we have already spoken. We may add that, being appointed to two ecclesiastical preferments, he bestowed the profits of both in charity, and resigned them as soon as he became master of Trinity. He left no property but books and unpublished manuscripts. Pure in his morals, he was the farthest possible from moroseness; amiable, lively, and witty in his temper and conversation, he was impatient of any looseness, irreverence, or censoriousness of speech, “being of all men,” says Dr. Tillotson, in his Address to the Reader, “I ever had the happiness to know, the clearest of this common guilt, and most free from offending in word; coming as near as it is possible for human frailty to do, to the perfect idea of St. James, his perfect man.”

His figure was low and spare, but of uncommon strength; and his courage, devoid of all alloy of quarrelsomeness, was approved in more than one instance related by the biographers of his peaceful life. It was among his peculiarities that he never would sit for his portrait; but some of his friends found means to have it taken without his knowledge, while they engaged his attention in discourse. There is a full length of him in the hall of Trinity, in fit conjunction with those of Newton and Bacon.

The earliest authority for Barrow’s life is a short memoir by his friend and executor, Mr. Hill, prefixed to the first edition of his works. Mr. Ward added some particulars, in his Lives of the Gresham Professors. The fullest accounts are to be found in the second edition of the Biographia Britannica, and in the life prefixed to Mr. Hughes’s edition of his theological works. In this the editor has given an analysis of the contents of each piece, calculated to assist the student to a thorough understanding of the author’s train of argument.