order. Thought is not without matter, nor matter without thought. Spinozism points out the intimate correlation between the two elements of being, but guards against identifying them, as materialism and idealism do, from opposite points of view.

But this gain is counterbalanced by a difficulty which seems to make for Cartesian dualism. Spinoza holds that one and the same thing (substance) is both extended and thinking, that is, inextended; hence, he flagrantly violates the law of contradiction. True, he anticipates this objection by declaring, in opposition to Descartes, that corporeal substance is no more divisible, in so far as it is substance, than spiritual substance; 1 and so prepares the way for the Leibnizian solution. But, on the other hand, he goes right on calling corporeal substance extended (res extensa).2 Now, indivisible extension is a contradiction in terms.

It was left to Leibniz to prove that there is nothing contradictory in the assumption that one and the same thing can be both the principle of thought and the principle of corporeal existence. He proclaimed the truth which is now accepted as a fundamental principle in physics, that the essence of matter does not consist in extension, but in force, and thereby turned the scales in favor of concrete spiritualism. It is a contradiction to hold that the same thing is both extended and inextended; it is not a contradiction to say that the same thing is force and thought, perception and tendency.

§ 56. Leibniz

The life of GOTTFRIED WILHELM LEIBNIZ, like his doctrine, forms the counterpart of Spinoza's. The illustrious Jew of Amsterdam was poor, neglected, and persecuted even

1 Eth., I., Prop. 13, Corollary: Ex his sequitur nullam substantiam et consequenter nullam substantiam corpoream, quatenus substantia est, esse divisibilem.

2 Id., II., Prop. 2.

to his dying day, while Leibniz knew only the bright side of life. Most liberally endowed with all the gifts of nature and of fortune, and as eager for titles and honors as for knowledge and truth, he had a brilliant career as a jurist, diplomat, and universal savant. His remarkable success is

reflected in the motto of his theodicy: Everything is for the best in the best of possible worlds. He was born at Leipsic in 1646, and died on the 14th of November, 1716, as Librarian and Court Counsellor of the Duke of Hanover, Privy Counsellor, Imperial Baron, etc., etc.

His principal philosophical writings are: Meditationes de cognitione, veritate et ideis (1684); Lettres sur la question si l'essence du corps consiste dans l'étendue (in the Journal des savants, 1691); Nouveaux essais sur l'entendement humain (in reply to Locke's Essay); Essais de Théodicée sur la bonté de Dieu, la liberté de l'homme et l'origine du mal (1710), dedicated to Queen Sophia Charlotte of Prussia; La monadologie (1714); Principes de la nature et de la grâce, fondés en raison (1714); finally, his Correspondence.1

1 His writings, most of which are brief, have been collected and edited by Raspe (Amsterdam and Leipsic, 1765); Louis Dutens (Geneva, 1768); J. E. Erdmann, Berlin, 1840; Foucher de Careil (Euvres de Leibniz, published for the first time after the original manuscripts, Paris, 1859 ff.); Paul Janet (2 vols., Paris, 1866, with the correspondence of Leibniz and Arnauld); [C. J. Gerhardt, Philosophical writings of Leibniz, 7 vols., Berlin, 1875-90. German writings ed. by G. E. Guhrauer, Berlin, 1838-40. Engl. translation of important philosophical writings by G. M. Duncan, New Haven, 1890; of the New Essays, by A. G. Langley, London and New York, 1893]. [G. E. Guhrauer, G. W. Freih. v. Leibniz, 2 vols., Breslau, 1842, 1846; Engl. by Mackie, Boston, 1845; Ludwig Feuerbach, Darstellung, Entwickelung und Kritik der leibnizschen Philosophie, Ansbach, 1837; 2d ed., 1844]; Nourrisson, La philosophie de Leibniz, Paris, 1860; [J. T. Merz, Leibniz (in Blackwood's Philosophical Classics), London, 1884; J. Dewey, Leibniz's New Essays concerning the Human Understanding (Griggs's Philosophical Classics), Chicago, 1888; E. Dillmann, Eine neue Darstellung der leibnizschen Monadenlehre, Leipsic, 1891.] For the Leibnizian doctrine of matter

Leibniz opposes to the dualism of extended or unconsci ous substance and inextended or conscious substance his theory of monads or inextended and more or less conscious substances. It seems that he derived the expression and the conception from Bruno's De monade and De triplici minimo1 (1591).

Both the physical and mental realms contain a series of phenomena which do not depend exclusively either on thought or on extension. If the mind is conscious thought and nothing but that, how shall we explain the countless minute perceptions (perceptions petites) 2 which baffle all ana Tysis, those vague and confused feelings which cannot be classified, in short, everything in the soul of which we are not conscious? The soul has states during which its perceptions are not distinct, as in a profound, dreamless sleep, or in a swoon. During these states the soul either does not exist at all, or it exists in a manner analogous to the body, that is, without consciousness of self. Hence there is in the soul something other than conscious thought: it contains an unconscious element, which forms a connecting link between the soul and the physical world.4

and monads see Hartenstein, Commentatio de materiæ apud Leibnizium notione, Leipsic, 1846; for his theodicy, J. Bonifas, Étude sur la Théodicée de Leibniz, Paris, 1863; for his doctrine of pre-established harmony, Hugo Sommer, De doctrina quam de harm, praest. L. proposuit, Göttingen, 1864; etc., etc. [Cf. also: Foucher de Careil, Leibniz, Descartes et Spinoza, Paris, 1863; E. Pfleiderer, Leibniz und Geulincx, Tübingen, 1884; L. Stein, Leibniz und Spinoza, Berlin, 1890; G. Hartenstein, Locke's Lehre von der menschlichen Erkenntniss in Vergleichung mit Leibniz's Kritik derselben, Leipsic, 1864; Frank Thilly, Leibnizens Streit gegen Locke in Ansehung der angeborenen Ideen, Heidelberg, 1891; and especially K. Fischer's History of Philosophy. — TR.]

1 [According to L. Stein (Leibniz und Spinoza), from F. Mercurius van Helmont.

TR.]

2 Nouveaux Essais, Preface.

Monadologie, § 11.

4 Nouveaux Essais, Book II., ch. IX. and XIX.; Principes de la na ture et de la grâce, § 4.

Moreover, what are attraction, repulsion, heat, and light, if matter is inert extension, and nothing but that? Cartesianism can neither deny nor explain these facts. Consistency demands that it boldly deny, on the one hand, the existence of order and life in the corporeal world, on the other, the presence in the soul of all ideas, sensations, and volitions which temporarily sink below the threshold of consciousness and attention, and reappear at the slightest inner or outer solicitation. It must unhesitatingly affirm that there is nothing inextended in the material world, and nothing unconscious in the spiritual world. But that would be to fly in the face of facts, and to assert an absurdity. No; extension, as the Cartesians conceive it, cannot of itself explain sensible phenomena. It is synonymous with passivity, inertia, and death, while everything in nature is action, movement, and life. Hence, unless we propose to explain life by death, and being by non-being, we must of necessity suppose that the essence of body consists of something different from extension.

S

And, indeed, does not the state of extension, which constitutes the nature of body, presuppose an effort or force that extends itself, a power both of resistance and expansion? Matter is essentially resistance, and resistance means activity. Behind the (extended) state there is the act which constantly produces it, renews it (extension). A large body moves with more difficulty than a small body; this is because the larger body has greater power of resist What seems to be inertia, or a lack of power, is in reality more intense action, a more considerable effort. Hence, the essence of corporeality is not extension, but the force of extension, or active force./ Cartesian physics deals with inert masses and lifeless bodies only, and is therefore identical with mechanics and geometry; but nature can be

ance.

1 Lettre sur la question de savoir si l'essence du corps consiste dans l'étendue (ed. Erdmann, p. 113).

explained only by a metaphysical notion that is higher than a purely mathematical and mechanical notion; and even the principles of mechanics, that is, the first laws of motion, have a higher origin than that of pure mathematics.1 This higher notion is the idea of FORCE. It is this power of resistance that constitutes the essence of matter. As to extension, it is nothing but an abstraction; it presupposes something that is extended, expanded, and continued. Extension is the diffusion of this "something." Milk, for example, is an extension or diffusion of whiteness; the diamond, an extension or diffusion of hardness; body in general, the extension of materiality. Hence, it is plain that there is something in the body anterior to extension (the force of extension). True metaphysics does not recognize the useless and inactive masses of which the Car

tesians speak. There is action everywhere. No body without movement, no substance without effort.3

2

Only the effects of force are perceptible; in itself it is an insensible and immaterial thing. Now force constitutes the essence of matter; hence matter is in reality immaterial in its essence. This paradox, which is also found in Leibniz, Bruno, and Plotinus, in principle overcomes the dualism of the physical and mental worlds. Though force forms the essence of that which is extended, it is itself inextended; it is therefore indivisible and simple; it is original; for composite things alone are derived and have become what they are; finally, it is indestructible, for a simple substance cannot be decomposed. A miracle alone could destroy it.

Thus far Leibniz speaks of force as Spinoza speaks of

1 Lettre sur la question de savoir si l'essence du corps consiste dans l'étendue (ed. Erdmann, p. 113).

2 Examen des principes de Malebranche (Erdmann, p. 692).

3 Éclaircissement du nouveau système de la communication des sul stances, p. 132.