LEIBNITZ
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LEIBNITZ
turned to Paris, hnd remained there fifteen months. In l(i7G he revisited England, and thence proceeded to Hanover by way of Holland. Here he entered upon his duties as counsellor, and — strange duties for a minister of state ! — employed himself in arranging and enlarging the library of his protector, and improving the drainage of his mines. His services were rewarded with a con- siderable salary, but the duke soon died (1G79). He found other employment, for he was never idle, and com- posed a treatise on The Eights o/Ainbassadorg, arguing the question of States' Eights, which has assumed such prominence in Germany in recent years. The new duke of Brunswick engaged Leibnitz to compose the History of the House of Brunswich. To prepare for the task, he visited southern Germany and Italy, consulting the learned, exploring monasteries, ransacking libraries, ex- amining old charters, deciphering mouldy manuscripts, and transcribing worm-eaten documents. Whatever he undertook he projected on a scale proportionate to his own vast comprehension and various knowledge, with little regard to the legitimate magnitude of the subject, or to the brevity of human life. He brought back from his wanderings an abundant supply of diplomatic mate- rials, which he arranged, and from -svliich he extracted extensive works, sometimes having little direct connec- tion with the Chronicles of Brunswick. The first-fruits of these collections were the Codex Juris Gentium Diplo- mat icus, of which the first volume was issued in 1693, in folio; the second in 1700, with the title Mantissa Codicis. Valualjle as w=ere the documents, the most valuable part of the work was the Introduction, reviewing the princi- ples of natural and international law, and sketching the reform of civil jurisprudence vdtimately achieved by Na- poleon. Other works of wide comprehension were due to these archajological researches : the demonstration of the descent of the Guelphic line from the Italian house of Estc ; the Accessiones Historic^ (1698, 2 vols. 4to, containing a multitude of unpublished papers), and the iScripto?-es Rerum Bitinsvireusinm. The first volume of this historical collection appeared iir 1707, folio ; the sec- ond in 1710; the third in 1711. These extensive accu- mulations were only materials to be employed for The Histori/ of the House of Brunstrich. In the Introduc- tion to the Corpus Scripiorvm Leibnitz discussed everj-- thing connected with the family, the realm, and the country of the Guelphs, investigating the traditions of the early tribes that dwelt on the Elbe and the Weser, tracing their changes and migrations, marshalling the passages of the ancient authors in which they were men- tioned, and examining their language and the mixture of their dialects. It inaugurated ethnological science and comparative philology. His inquiries, however, stretched far beyond the incunabula r/entis, and contem- plated the primitive condition of the abode of the race. This preliminary outline is given in the Protogwa (1693), ■\vliieli founded the modern sciences of geology and jihys- ical geography. It is interesting to compare this frag- mentary sketch with the Vvkjur Errors of Sir Thom- as Hrowne, and to note the immense stride which was made by Leibnitz. Of the main worl^, to which this es- say was to be introductor}- — the History of the House of Jhinisirick — only a brief and imperfect outline was ever drawn by the accomplished author. It was published after his death by Eccard, in the A eta Eruditorum, in 1717.
These historical labors were the real task of the life of Leibnitz. But the long years of plodding industry were abundantly fiUed with other enterprises, and it is to them that his reputation is mainly due.
By his exertions chiefly, the A eta Ertiditorum — a sci- entific and philosophical periodical — was established (vol. i, Leipsic, 1682). To this he contributed largely, and in its pages appeared many of his most luminous discoveries and suggestions. In it was published his Meditationes de Coc/nitione, Veritate et Idiis (1681\ pro- pounding his modifications of the Cartesian doctrine of knowledge. In the same year, and in the same work,
appeared his rules for the Differential Calculus, the germs of which had been indicated in his Theoria Motus Ab- stract thirteen years before. He gave no demonstra- tions ; these were divined with wonderfid ingenuity, and promulgated by the Bernouilli brothers. In 1687 the world was enriched by Sir Isaac Newton's Princijna Mathematica Fhilosophice Naturulis, which employed a mathematical device closely analogous to the Calculus of Leibnitz. A bitter controversy jn regard to priority of discovery and originality of invention sprung up be- tween the partisans of these great mathematicians. It is scarcely yet terminated. The rigorous and repeated examination of the question justifies the conclusion that both had independently discovered corresponding pro- cedures. The histor)^ of inventions is full of such coin- cidences. There is sufficient difference between the Flu- ents and Fluxions of Newton and the Calculus of Leib- nitz to indicate the originality of each. Neither was the first to enter upon this line of inquiry. To Leibnitz is specially due the acquisition of the powerful instru- ment by which so many of the triumphs of modern sci- ence have been won. In this connection a passing ref- erence may be made to his Arithmetica Binuria (1697) — a method of notation and computation employing only the symbols 1 and 0; and also to the Philosophy of Iit- fnity, long meditated, but never made pidjlic.