Page images
PDF
EPUB

The soul of man, which is one, is both sensitive and rational; and the conflict between its inferior and superior parts is nothing else but a struggle between the motions which the body, by means of its animal spirits, and the soul, by its own volition, are at the same time endeavouring to excite in the pineal gland. By the result of this contest, every one may judge of the strength or weakness of his soul. The soul acquires the dominion over the body by means of firm and clear decisions concerning good and evil, produced by the contemplation of truth, which it determines to follow without suffering itself to be seduced by present passion. The passions belong to the body, and are to be imputed to the soul only as it is united to the body. Their use is, to excite the mind to exert those volitions which are necessary to the preservation or perfection of the body, and the attainment of that which is in its nature good. All the passions are useful, and only become injurious by excess. The general remedy against the excess of the passions is, to consider all the appearances which they present to the imagination as deceitful, and to postpone volition and action till the commotion which they have excited in the blood is appeased, or, where immediate action is necessary, to follow reason in opposition to passion. Since nothing beyond our own thoughts is absolutely in our own power, it is wiser to endeavour to subdue ourselves than fortune, and to change our own desires than the order of the world.

Animals are not only destitute of reason, but probably of all thought, and perform their various functions as mere automata, excited to motion only by means of animal spirits, which act upon the nerves and muscles.

This last extravagant opinion Des Cartes has been suspected of borrowing from a Spanish writer, Gomes Peiræra, by whom it was maintained in his Margarita Antoniana; but it is more probable that it was a conclusion originally deduced from his notion of the animal spirits in the economy of human nature.

Although some parts of the Cartesian system appear to have been derived from the Grecian philosophy; particularly the notion of innate ideas, and of the action of the soul upon the body, from Plato; the doctrine of a plenum

from Aristotle; and the elements of the doctrine of vortices from the Atomic school of Democritus and Epicurus; Des Cartes must, nevertheless, be confessed to have discovered great subtlety and depth of thought, as well as fertility of imagination, and to have merited a distinguished place among the improvers of philosophy. But his labours would have been more valuable, had he not suffered himself to be led astray into the romantic regions of hypothesis, by the false notion, that the nature of things may be better understood by endeavouring to account for appearances from hypothetical principles, than by inferring general principles from an attentive observation of appearances. His fondness for hypothesis led him to confound the ideas of attribute and substance, as in his definition of matter and space; and those of possibility and probability, as in his doctrine of vortices. Even his celebrated argument for the existence of God (which by the way, was maintained before his time by the Scholastic Anselm) confounds the idea of an infinite being with the actual existence of that being, and substitutes a mere conception of the meaning of a term, in the place of the idea of a being really and substantially existing. Hence, though Des Cartes is by no means to be ranked among the enemies of religion, as he was by many of his bigotted contemporaries; though it be even true, that his whole system is built upon the knowledge of God, and supposes his agency, it must nevertheless be regretted, that, in establishing the doctrine of Deity, he forsook the clear and satisfactory ground of final causes, and had recourse to a subtle argument, which few can comprehend, and with which fewer still will be fully satisfied.

The system of Des Cartes, notwithstanding its defects, had so much subtlety, ingenuity, and originality, that it not only engaged the universal attention of the learned, but long continued, in the midst of all the opposition which is met with from the professed enemies of innovation, to be zealously defended by many able writers, and to be publicly taught in the schools, throughout all Europe. Till at length, when the more sober method of philosophizing, introduced by Lord Bacon, began to be generally adopted, and the fabrications of romantic theories gave way to the

experimental study of nature, the system of Des Cartes, like "the baseless fabric of an air-vision," has disappeared, and has scarcely "left a wreck behind."31

SECT. VII.

Of Godfred William Leibnitz.

WHAT Des Cartes undertook in France was at the same time attempted in Germany by Leibnitz, a distinguished ornament of his age and country.

Godfred William Leibnitz 3 was born at Leipsic, in the year 1646. He was the son of a learned professor of morals in the university of that city. In his childhood, such was his thirst after learning, that, not contented with the daily instruction of his preceptors, he frequently withdrew into his father's study to read the ancients. Livy and Virgil were his favourite authors: and he was so intimately conversant with the latter, that, even when he was an old man, he could repeat from memory almost the whole of his poems. This early and assiduous attention to classical learning, laid the foundation of that correct and elegant taste which appears in all his writings. At fifteen years of age, Leibnitz became a student in the university of Leipsic, where, under the direction of able masters, he prosecuted with unusual success the various studies of law, medicine, philosophy, and theology, and made himself well acquainted with many eminent writers in each. In the

31 Vidend. P. Daniel Iter Cartes. per Mund. p. i. p. 14. Kortholt. Ep. Leibn. v. iii. Thomas Hist. Sap. t. ii. p. 114. Spanhem. ep. de Noviss. Dissid. in Belgio. Pfaff. Hist. Lit. Theol. P. ii. p. 299. Sagittar. Intr. Hist. Eccl. P. i. p. 925. P. ii. p. 627. Benthem. Stat. Eccl. Schol. Bat, p. ii. c. 4. Cudworth Int. Syst. c. v. § 1. Parker Disp. iii. de Deo. p. 221. vi. p. 489. Huet. de Rebus suis, 1. vi. p. 162, Huet. Mem. pour Cartesianisme. Rapin. Reflex. § 23. Ritter de Religione Cartesii. Petermanni Vind. Phil. Cart. Lips. 1704. Alberti Diss. de Cart. et Loccuanism. Monmor. Diss. de Physique de M. de Cartes, 1718.

32 Elogie de Leibnitz par Pontenelle. Guntheri Ludovici Hist. Phil. Leibnizian. Lips. 1737, 8vo. Fabric. Hist. Bibl. suæ, v. i. p. 317. Reimann. Hist. Lit. Ger. p. iii. p. 576. p. iv. p. 147. p. v. p. 262. Stollii Hist. Lit. p. ii. c. i. Niceron, Mem. t. ii. p. 64.

university of Jena, where he finished his academical studies, the principal objects of his attention were history, law, and mathematics. On his return home, he continued to study philosophy, particularly in the writings of Plato and Aristotle, whom he endeavoured to reconcile. In 1666, he took his degree in philosophy, and in the public disputations upon this occasion, displayed uncommon ability. He published, the same year, his Ars Combinatoria, "Combinatory Art;" a work intended to shew in what manner universal arithmetic may be applied to the elucidation of other sciences. This piece was accompanied with "A Mathematical Demonstration of the Existence of God." Though this early production was not entirely approved by his own more mature judgment, it bore evident marks of an inventive genius.

In the midst of his philosophical and mathematical speculations, Leibnitz had never neglected the study of jurisprudence; and he made himself so perfectly master of this science, that, in 1668, he published his Nova Methodus docendæ discendæque Jurisprudentiæ,33 "New Method of teaching and learning Jurisprudence," which gained him great applause, and introduced him to the notice of the Elector of Mentz, by whom he was employed in affairs of state. Still, however, he persevered in his philosophical inquiries; and when he found it in vain to attempt to collect any consistent system from former philosophers, he determined to exercise his own invention in framing a new hypothesis. This first effort of his philosophical genius produced a work, entitled Theoria Motus Concreti, "A Theory of Concrete Motion," inscribed to the Royal Society in London; the principles of which were further explained in another work, Theoria Motus Abstracti, "The Theory of Abstract Motion," inscribed to the French Academy of Sciences. The solution of the phenomena of nature, proposed in these treatises, the author afterwards abandoned for his doctrine of Monads.

The mathematical speculations of Leibnitz were original and profound. During a visit which he made at Paris in 1672, he gave such proofs of his eminent skill in the higher geometry, as excited the general admiration of the French * Francof. 12mo.

mathematicians. A royal pension was offered him if he would remain in France: but his attachment to the Protestant religion induced him to decline the proposal. Going over, at this time, into England, he formed an acquaintance with several eminent philosophers, and among the rest with Newton. Upon the death of his patron, the Elector of Mentz, he returned into Germany, and was admitted into the service of Frederic Duke of Brunswick Lunenburg. After another visit to his mathematical friends in France and England, he settled at Hanover, and became a member of the Duke's Aulic Council. In this situation, his civil labours did not prevent his philosophical lucubrations. It was at the beginning of the year 1677, that he first mentioned his mathematical invention of Differentials to Newton, who had just before written to Leibnitz an account of his own invention of Fluxions. He also, about the same time, brought to light some discoveries which he had made in mechanics and chemistry. His Notitia Optica Promote, "Hints of Improvement in Optics," relates a new method of polishing optical glasses, on which subject he corresponded with Spinoza, who was an excellent optician. Memoirs of experiments and observations made by Leibnitz on various subjects in natural philosophy are preserved in the Leipsic Journal, entitled, Acta Eruditorum, "Works of the Learned," in which, from the year 1683, he had a considerable share. One of his most valuable pieces, preserved in this periodical work, is his "Thoughts on Knowledge, Truth, and Ideas."

Whilst Leibnitz was employed in collecting, at the rcquest of the Duke of Lunenburg, materials for a history of the House of Brunswick, he availed himself of the opportunities which his journies on this business afforded him, for enlarging his knowledge of nature and the arts. Upon his return, he pursued with indefatigable industry, several objects of entirely different kinds: he engaged in further mathematical and philosophical researches; he maintained a theological dispute with Pellisson; and he wrote an important work on the Law of Nations, entitled, Codex Juris ; Gentium diplomaticus. No sooner was this elaborate treatise finished, than he applied his thoughts to the great design of renovating the science of metaphysics, and particu

[blocks in formation]
« PreviousContinue »