to the university of Altdorf, where he received his degree in law the same year. Leibnitz thus belongs to that class of distinguished philosophers who have been bred to the legal profession. Jurisprudence naturally engaged his attention, and at the age of twenty he published his thesis, followed afterwards by an essay on the logic of law, both remarkable contributions to the theory of that part of science. "There was only one man in the world," says Hallam, "who could have left so noble a science as philosophical jurisprudence for pursuits of a still more exalted nature, and for which he was still more gifted, and that man was Leibnitz. He passed onwards to reap the golden harvests of other fields."
Leibnitz led a somewhat desultory life for several years after he had taken his degree in law. A professional chair at Nuremberg, where he lived for a short time, was soon within his reach, but was declined by one whose projects of reform in philosophy were too comprehensive to be confined within the limits of a small German university. At Nuremberg, in 1667, he met the distinguished statesman and scholar, the Baron Von Boineburg, who had been long prime minister of the elector of Mentz, and who was then living at Frankfort-on-the-Maine. Boineburg in a great measure determined the subsequent life of Leibnitz. In that year the young philosopher accepted the invitation of the baron to transfer his residence to Frankfort, where he became his secretary, and enjoyed the society of men of letters and affairs. During his residence at Frankfort he was patronized by the elector of Mentz, and was much engaged in legal and diplomatic labours as well as in literary pursuits; yet his mind was all the time animated by the great idea of his life. He found time to edit the "Antibarbarus" of the Italian Nizolius, and besides was active in politico-ecclesiastical affairs. Boineburg, who was born in the Lutheran church, had joined the communion of Rome, and was interested in a scheme for the union of the Lutheran and Romish churches. This eclectic movement, in which Leibnitz felt a characteristic sympathy, was not forgotten by him at a later period in his life. The years which immediately followed his residence at Nuremberg and Mentz, are especially notable as the commencement of that unparalleled literary and scientific intercourse organized by Leibnitz, and in which he always appears as the centre of the thinking spirits of his time. He may be said to have founded in the course of his life the European commonwealth of letters, and to have restored in part that community of intelligence in Christendom, of which the universities were the organ, until the Reformation dissolved their organic unity. His political relation to the elector occasioned visits by Leibnitz to other courts in and around Germany, and also to Paris, where he went in 1672, to divert Louis XIV. from a suspected attack on Germany, by the project of a French crusade to Egypt and the East. The four following years were for the most part spent in Paris by Leibnitz, in the capacity of councillor to the elector of Mentz. In the circles of that brilliant metropolis he was a conspicuous object, and he found the place so congenial to him that he more than once formed the plan of making the French capital his permanent residence. Moliere and Racine were then great names in the world of letters; Malebranche and Arnauld in philosophy. With Arnauld and Huet he had frequent intercourse, and Malebranche was afterwards the object of his metaphysical criticism. In 1673 he visited London for a short time, where he became a member of the Royal Society, and made the acquaintance of many English savans. To this period in his life belongs his immortal discovery of the differential calculus, which has placed him in the foremost rank of mathematicians. It was followed by the famous controversy regarding an alleged priority of discovery by Sir Isaac Newton. In this controversy were discussed the difference between the calculus of Leibnitz and the Newtonian method of fluxions, the time of the discovery of the former, and its superiority over the latter. Leibnitz communicated his calculus to Newton in 1677, after he had received a letter from Newton containing his fluxional method concealed in two sentences of transposed characters. Newton then broke off the correspondence. Leibnitz promulgated his discovery in 1684 in the "Acta Eruditorum," but made no allusion to his former correspondence with Newton, whose Principia, containing an explanation of the fluxionary method, appeared in 1686. The publication of the Principia, which Leibnitz habitually disparaged, widened the breach between the two philosophers. An angry controversy ensued (in which the Royal Society of London was called in as umpire), which disturbed the last years of these great men, and probably contributed to the inadequate estimate of Leibnitz so long prevalent in England. But we must return to the chronological order of events. In 1676 the duke of Hanover, for the third time, invited Leibnitz, who was still in Paris, to make the Hanoverian capital his residence, offering him the offices of royal councillor and librarian. On this occasion he accepted the invitation, and quitted the city where, a short time before, he proposed to find his home. In returning to Germany he made a circuit through England and Holland. When in Holland he visited Spinoza at the Hague, about a year before the death of the Dutch philosopher. To this interview Leibnitz refers in his "Théodicée." From about 1674 may be dated the intercourse of Bayle with Leibnitz.
The year 1676, when he was thirty years of age, is an era in the life of our philosopher. Then commenced that connection with the court of Hanover which lasted during the remaining forty years of his life. Henceforward Hanover was his home, in which this sage held a succession of political and literary offices under Duke John Frederick and his successors, the Electors Ernest Augustus and George Lewis—the latter of whom became George I. of England two years before the death of Leibnitz. The variety of his aims during these forty years is marvellous, and amid them all the development of his speculative genius continued to advance. History, politics, languages, mathematics, geology, chemistry, medicine, metaphysics, and theology, in turn secured his attention, and his busy spirit collected the varied learning of each department. In history he worked for years on the antiquities of the house of Brunswick and the early annals of Germany. These historical researches became the great labour of his life. Experience of the difficulties of archæological research suggested to him the comparative anatomy of languages as a means for aiding his efforts to travel back into the past. To the study of languages he accordingly applied himself with extraordinary zeal. He laid ambassadors and jesuit missionaries under contribution for philological facts. In prosecuting this one department of investigation, he maintained an immense correspondence. Not content with the records of the past contained in the words and works of man, he interrogated the globe itself. In the speculations on the physical vestiges of its early history, contained in his posthumous treatise, entitled "Protogæa," we find most interesting anticipations of recent geological hypotheses, and a remarkable familiarity with geological facts. Throughout the forty years of his connection with the court of Hanover, Leibnitz maintained his literary intercourse with unabated energy. His correspondence forms a very important part of his philosophical writings. In this period he, in fact, settled and extended the foundations of the literary republic of Europe. In 1687 and the following years, by the wish of the duke of Hanover, he visited various parts of Germany and also Italy, in quest of information respecting the early history of the house of Brunswick, but with various other important aims, which naturally occurred to a mind of comprehensive sympathies. He travelled up the Rhine, explored the libraries and archives of Bavaria and Vienna, and extended his acquaintance with learned men. In 1689 he passed from Vienna into Italy, where he had much intercourse with statesmen and men of letters. After an absence of nearly three years he returned to Hanover to resume his labours as keeper of the national library, and to attend to affairs of state. In 1696 he was appointed privy councillor of justice—one of the highest judicial offices in the country. In these years the examination and arrangement of the historical treasures he had collected in Austria and Italy engaged much of his attention. He might probably have lived to see the publication of his "Annales rerum Brunsvicensium," had he not adopted too comprehensive a plan, and also sought to investigate exhaustively the ultimate grounds and philosophical relations of the results which he recorded. In 1700 he was engaged in a plan for securing a closer union of the courts of Hanover and Brandenburg, a negotiation which in itself and its consequences has associated his name with the intellectual and politico-ecclesiastical history of Prussia. He was the chief founder of the famous Berlin Academy of Sciences, meant to be a centre of German literary and scientific intercourse and effort. He was unfortunately unsuccessful in his endeavours to establish a similar institute at Vienna on a still more comprehensive plan. He was much interested in the civilization and political relations of the rising Russian empire,
