History of Philosophy
by
Alfred Weber§ 60. Progress of Materialism (1)
The empirical school's contempt for metaphysics refers only to the dualistic metaphysics, and not to the system of Hobbes, Gassendi, and Democritus. Philosophy gradually abandoned dualism. It might have adopted the immaterialism of Berkeley and Collier; but this hypothesis, though satisfying the monistic instinct, had against it the evidence of facts and the native realism of the French and English minds. Hence, philosophy continued, in spite of Berkeley, to concede primary qualities to bodies. True, tastes, smells, colors, sounds, and temperature are nothing but sensations of the subject which perceives them, and do not exist, as such, in the things themselves and outside of us. But extension, impenetrability, figure, motion, etc., are primary qualities, i.e., inherent in a reality external to and independent of our perception, and of these qualities bodies, or matter, are composed. Hence, the latter has objective reality, and does not owe its existence to our sensation, i.e., to the mind, as Berkeley claimed.
The belief in the objective and absolute existence of bodies persisted. Hobbes's assertion that all substances are bodies, and the hypothesis of Locke, according to which matter can think, seemed less presumptuous when Leibniz, repudiating the Cartesian teaching, substituted for extended matter, matter endowed with force, (2) a kind of intermediate reality, or connecting link between brutal matter and pure spirit. This conception made it possible for one to assume a real and physical action of body on mind, without fear of materializing spirit. Experience, moreover, on whose territory the new philosophy had firmly established itself for all time to come, advanced the cause of materialism by its emphatic declaration that body acts on mind, and that the mental world depends on the physical world.
JOHN TOLAND (1670-1721), a fellow-countryman. of Berkeley, whose genius, character, and fate remind one of Bruno and Vanini, becomes the champion of materialism in his Letters to Serena (3) and his Pantheisticon (1710). Matter is not, according to him, the "extended substance" of Descartes, an inert, lifeless mass that receives its motion from a transcendent deity; it is an active substance, that is, force. Extension, impenetrability, and action are three distinct notions, but not three different things; they are simply three different modes of conceiving one and the same matter. (4) Matter is originally and necessarily active, and hence does not receive its motion from without; motion is its essential and inseparable property, -- as essential and inseparable as extension and impenetrability. Since matter as such is force, motion, and life, we do not need either a soul of the world, in order to explain universal life, or an individual soul as the source of psychical life and the vital principle of the organic body. The hylozoistic and vitalistic hypothesis is based on the erroneous conception that matter is inert, that it is merely the theatre and the means, and never the source, of action. The abandonment of this false view will result in the collapse of the dualistic theory. Body ceases to be a substance that cannot think, and soul or mind is simply one of its functions. Furthermore, thought does not belong to substance in general, as Spinoza assumes; (5) matter, though active, is unconscious in itself, and becomes conscious only in the brain (a view already held by Democritus). There can be no thought without a brain; thought is the function of this organ, as taste is a function of the tongue. (6)
Less bold in form but the same in substance are the conclusions of the Observations on Man, (7) the work of the physician and naturalist DAVID HARTLEY (1704-1757). There can be no thought without a brain. The brain is not the thinking subject; the soul is the thinking subject. But though the soul is entirely distinct from the body, it cannot be regarded as essentially different from corporeal substance. The action of the brain on thought is established by the facts, and proves conclusively that matter and mind differ in degree and not in essence, for there can be no reciprocal action between two essentially different substances. The so-called material world represents an ascending scale of substances, or rather forces; these become more and more refined and spiritualized, as we pass from mineral masses to light. The distance from the stone to the luminous agent is so great that one is tempted to oppose the latter to the former as spiritual substances are opposed to material substances. And yet no serious thinker would dream of removing optical phenomena from the domain of physics. The infinitely subtile, refined, and intangible substance called light is none the less matter. Why, then, should we not assume that the above-mentioned series continues beyond ether, and finally ends in thought or soul? This mental agent is so far removed from light, in fineness and mobility, as the latter is from the stone and wood, without on that account ceasing to be matter.
The white medullary substance of the brain and the spinal marrow constitute the seat of sensation and the source of voluntary motion. Every modification of this substance is accompanied by a corresponding modification in our soul-life. The modifications of the cerebral and nervous substance, corresponding to those of the soul, are vibrations or "tremblings" produced by external excitations and transmitted through the sensory nerves to the central portion of the brain. The nervous substance, which may be perceived by our senses and experimented on, most probably contains an infinitely subtile and mobile fluid, which might be identified with electricity (8) and ether. The vibrations of this fluid or ether cause sensations. When these vibrations are reproduced a certain number of times, they leave traces; these traces are our ideas. Our soul-life depends entirely on the association of these ideas, which, in turn, depends on the association of sensations, i.e., vibrations of ether or nervous fluid. True, these vibrations are not, as yet, sensations; they affect the body, and sensations affect the soul; they belong to the domain of physiology, and sensations belong to the domain of psychology. But the fact that the latter are effects of the former conclusively proves that corporeal substance is analogous, if not identical, with thinking substance.
JOSEPH PRIESTLEY (1733-1804), theologian, philosopher, and naturalist, to whom we are indebted for the discovery of oxygen, (9) considers, in his Disquisitions relating to Matter and Spirit (10) the proofs of his predecessors, ancient as well as modern, in favor of the materiality of the soul, and adds some arguments of his own:
1. If the soul is an inextended substance, it does not really exist in space; for to be in space is to occupy a portion of it, be it never so small. Hence the soul is not in the body: such is the absurd conclusion which Cartesian spiritualism compels us to draw.
2. Principia non sunt multiplicanda prœter necessitatem. Now, there is no need of assuming for thought a new and essentially different principle from the principles by which science explains the phenomena of light, electricity, etc., which show striking similarities with psychical phenomena.
3. The development of the soul runs parallel with that of the body, on which it wholly depends.
4. There is not a single idea of which the mind is possessed but what may be proved to have come to it from the bodily senses, or to have been consequent upon the perceptions of sense.
5. Our ideas of external objects, -- the idea of a tree, for example, -- consist of parts, like their objects. How is it possible that such ideas should exist in an indivisible and absolutely simple soul?
6. The soul ripens and declines. How can an absolutely simple being without parts be increased, modified, or diminished?
7. If man has an immaterial soul, every animal, which feels, perceives, remembers, combines, and judges, must have one also.
8. What is the use of the body, and why is the soul associated with it, if it can feel, think, and act independently of it?
9. Spiritualism claims that an extended being cannot think. But is it not still more inconceivable that an inextended entity -- a simple mathematical point -- should contain an infinite number of ideas, feelings, and volitions, as the human soul does? The soul is a reality no less manifold than the universe which it reflects.
10. The will is determined by motives, reasons, and arguments. Hence, spiritualism objects, if the soul is material, matter is moved by motives, reasons, and arguments. But the matter which materialism invests with the faculty of thinking is not the gross and inert mass which it is at first supposed to be; it is the ether, that mysterious agent which we know only by its manifestations, but which we assume to be the basis of intellectual phenomena as well as of extension, impenetrability, and movement. Besides, it may be said, in answer to the spiritualists, that if the theory of "matter influenced by motives" is objectionable to them, their "simple substance influenced by an extended substance" (in sensation and perception) is no less objectionable to the materialistic thinker.
11. If the soul, says spiritualism, is composed of parts, atoms (or, as we should say nowadays, of living cells of gray cortical substance), how can it be felt as a, unity? How does it become conscious of the me? (11) This feeling, this perception of the unity which is called the ego, is conceivable only in a real individual, in a unity, monad, or atom, and not in a sum of monads, atoms, or individuals, not in the whole nervous system. For a sum or whole is merely an idea, a mental being; its parts alone have real existence (nominalism). Hence these (the monads, atoms, or individuals making up the nervous system) can feel themselves, each for itself and separately, as unities or I's; but the nervous system, the whole, cannot, for the whole is not an individual, an objective and existing reality. This, as Priestley himself confesses, (12) is the strongest, and, in fact, the only serious argument that spiritualism can oppose. (13) How can the one arise from the many? He declares that he cannot explain the difficulty, but that, if it really is a difficulty, it exists for spiritualism as well. Psychological consciousness is nothing but plurality reduced to unity, or unity derived from plurality, or, in a word, the synthesis of the one and the many, i.e., an inexplicable mystery. Spiritualism is as unable to tell how a multitude of ideas, feelings, and volitions can constitute the unity of self, as materialism is powerless to explain how a multitude of atoms can form a unity. Hence, spiritualism has no advantage over its adversary in this respect.
12. It is objected that the soul wars against the body, that it is possessed of a self-moving power, while the body needs a foreign mechanical impulse, that the body alone becomes weary and never the soul; finally, that, if the human soul is material, God himself ceases to be a pure spirit. Priestley replies that there are also conflicts between the different tendencies of the soul, and yet that spiritualism does not dream of referring each of these tendencies to a principle or a different substance; that the body is not inert, as was believed before the days of Leibniz, and that no substance is without force; that thought fags and exhausts the brain, which is refreshed in sleep; finally, that we cannot extend our reasonings concerning finite beings to the infinite, but that the "materiality" of God is more consistent with the dogma of omnipresence than the opposite view.
Priestley appeals to the Bible, and believes that his system can be reconciled with Christianity and even with Calvinism. (14) French materialism, however, does not share these illusions. In the Testament de Jean Meslier, (15) which Voltaire made public, we find the bold utterances of Toland repeated. The same may be said of the writings of the physician, Julien Offroy DE LA METTRIE (16) (1709-1751), who was one of the first outspoken materialists in France. Curiously enough, this leader of the opponents of spiritualism is a disciple, not of Toland, but of the man whom French spiritualism recognizes as its head: Descartes. We must remember that Descartes was not only the author of the Meditations and the dualistic hypothesis, but that he wrote the Treatise on the Passions of the Soul, and founded the modern mechanical theory. Descartes not only proved the existence of God and the spirituality of the soul, (17) but also showed "how all the limbs can be moved by the objects of the senses and by the spirits WITHOUT THE AID OF THE SOUL; " (18) that it resides in the pineal gland; that memory presupposes cerebral impressions; that animals are machines; that the intellectual phenomena which we discover in them can and must be mechanically explained. The advance from the animal-machine of Descartes to the homme-machine is slight; and La Mettrie makes it. If the animal can feel, perceive, remember, compare, and judge, without the aid of an immaterial soul, simply by means of its nervous and cerebral organization, there is no reason why we should concede a soul to man, whose sensibility, will, and understanding are merely more highly developed animal functions. Man is not an exception; he does not form a separate and privileged caste in universal nature. The laws of nature are the same for all. There can be no difference in this respect between men, brutes, plants, and animals. Man is a machine, but a more complicated machine than the animal: "he is to the ape or the most intelligent animals, what Huyghens's planetary pendulum is to a watch made by Julien Leroy."
This developed animal did not fall from the clouds, nor did it arise, ready-made, from the bowels of the earth. It is not the work of a supernatural creator, the realization of an idea: it owes its origin to a natural evolution which gradually evolves more and more perfect forms from the elementary organisms. The human species is no more a separate creation than the other animal and vegetable species; its present form has been evolved from lower animal forms, slowly and by progressive stages. The evolutionistic and transformistic conception, familiar to ancient philosophy, (19) reappears, in various forms, but wholly conscious of its aims, in the Pensées sur l'interprétation de la nature of DENIS DIDEROT, (20) in the work, De la nature, of ROBINET, (21) in the Palingénésie philosophique of CHARLES DE, BONNET, (22) precursors of Lamarck and Darwin. According to Diderot, the entire universe is an endless fermentation, a ceaseless interchange of substances, a perpetual circulation of life. Nothing lasts, everything changes, -- species as well as individuals. Animals have not always been what they are now. In the animal and vegetable kingdoms, individuals arise, grow, decline, and die. Can we not say the same for entire species? Now, there is an affinity, and perhaps identity, between kingdoms, just as between species. Thus, who can ever exactly determine the boundaries between plants and animals? Plants and animals are defined in the same way. We speak of three kingdoms, but why should not one emanate from the other, and why should not the animal and vegetable kingdoms emanate from universal heterogeneous matter? The evolution is wholly mechanical. Nature, with its five or six essential properties, such as potential and active force, length, breadth, depth, impenetrability, and sensibility, which exists potentially in the inert molecule, and matter, suffices to explain the world. We should not search for designs (intentions) where there are only accidental facts. The spiritualists say: Look at man, that living proof of final causes! What do they mean? The real man or the ideal man? Surely not the real man, for there is not a perfectly constituted, perfectly sound man on the entire surface of the earth. The human species consists of an aggregation of more or less deformed and unhealthy individuals. Now, why should that make us sound the praises of the alleged creator? Praises, indeed! We have nothing but apologies to offer for him. And there is not a single animal, a single plant, a single mineral, of which we cannot say what has just been said of man. Of what use are the phalanges in the cloven foot of the hog? Of what use are the mammæ in males? The actual world is as a day-fly to the millions of real or possible worlds of the past and future; it is what the insect of Hypanis is to man, who sees it live and die in the passing of a day. The day of a world lasts a little longer, that is all.
These conceptions of the world and man are shared by HELVÉTUS, (23) who, like Thomas Hobbes and Mandeville, (24) considers egoism and self-interest as the true and sole motive of our acts; by the mathematician D'ALEMBERT, (25) whose philosophy reveals a delicate tinge of scepticism, which distinguishes it favorably from its environment, and brings it nearer to criticism; by the political economists TURGOT (26) and CONDORCET, (27) who construct a positive philosophy of history, based on the necessity of human actions and the law of continued progress; by the Baron d'HOLBACH, (28) whose Système de la nature, published at London, 1770, under the pseudonym of Mirabaud, is a complete theory of ontological and psychological materialism. Matter and motion: these two words sum up everything. Matter and motion are eternal. The universe is neither governed by a God nor by chance, but by immutable and necessary laws. These laws do not depend on a personal power capable of modifying them, nor do they form a brutal necessity, a Fate hovering above things, a yoke imposed upon them from without: they are merely the properties of things, the expression of their innermost nature. The universe is neither an absolute monarchy à la Duns Scotus, nor a constitutional monarchy à la Leibniz, but a republic. Theism is the sworn enemy of science. Pantheism is merely a shamefaced theism, or atheism in disguise. The mechanical theory sufficiently explains all things. There is no finality in nature. Eyes were not made for seeing, nor feet for walking, but seeing and walking are the effects of a certain arrangement of atoms, which, if different, would produce different phenomena. There is no soul apart from nervous substance. Thought is a function of the brain. Matter alone is immortal; individuals are not. The freewill of the indeterminists is a denial of the universal order. There are not two separate realms and two series of laws, -- physical laws and moral laws, -- but one undivided and indivisible universe, subject, in all its parts and at all periods, to the same necessity.
Finally, on the eve of the Revolution, the physician CABANIS (1757-1808), in his Considérations générales sur l'étude de l'homme et sur les rapports de son organisation physique avec ses facultés intellectuelles et morales, (29) formulated the principles of psychological materialism with such frankness and vigor as have never been excelled. Body and mind are not only most intimately connected; they are one and the same thing. The soul is body endowed with feeling. The body or matter thinks, feels, and wills. Physiology and psychology are one and the same science. Man is simply a bundle of nerves. Thought is the function of the brain, as digestion is the function of the stomach, and the secretion of bile the function of the liver. The impressions reaching the brain cause it to act, just as the food introduced into the stomach sets that organ in motion. It is the business of the brain to produce an image of each particular impression, to arrange these images, and to compare them with each other for the sake of forming judgments and ideas, as it is the function of the stomach to react upon food in order to digest it. Intellectual and moral phenomena are, like all others, necessary consequences of the properties of matter and the laws which govern beings. (30)
On this latter point, philosophers, be they conservative or radical, dogmatic or sceptical, jurists and littérateurs, naturalists and physicians, agree. By subjecting the Deity himself to laws, MONTESQUIEU simply denies God as an absolute personal power. His God is the nature of things, in which are grounded the necessary relations which we call laws. (31) VOLTAIRE is a deist, but he assumes, with Locke, that matter can think. (32) J. J. ROUSSEAU is a spiritualist in his way, but nature, which we have abandoned and to which we must return, is his God also. (33) The pioneers of German literature, Lessing, Herder, and Goethe, combine with the highest idealism the same naturalistic and monistic, if not materialistic, tendency. What united these different thinkers was their outspoken or secret opposition to Cartesian dualism, which set up a separate order of things, called free spiritual substances, not subject to the laws of nature, a kind of caste or privileged aristocracy. Equality before the law of nature, and (in view of the failure of sense-perception and speculation to establish the freedom of indifference) determinism for all, without excepting even the Supreme Being: these were the watchwords of the philosophers until they became the watchwords of the Revolution in 1789.
1. See Damiron, Mémoires pour servir à l'histoire de la philosophie au dix-huitième siècle, §§ 8 ff.
2. Cf. pp. 346 f.
3. Letters to Serena (Serena is Queen Sophia Charlotte of Prussia, the friend of Leibniz, at whose court Toland lived from 1701-1702), followed by a Refutation of Spinoza, and a treatise on movement as the essential property of matter (London, 1704). [Cf. G. Berthold, John Toland und der Monismus der Gegenwart, Heidelberg, 1876
4. Letters to Serena, pp. 230 ff.
5. Deus est res cogitans (Eth., II., Prop. 2).
6. Pantheisticon, p. 15.
7. Observations on Man, his Frame, his Duty, and his Expectations, London, 1749; 6th ed., 1834. [Cf. G. S. Bower, Hartley and James Mill (Engl. Philosophers), London, 1881; B. Seboenlank, Hartley und Priestley, die Begründer des Associationismus in England, Halle, 1882. - Tr.]
8. As has been done, in our century, by the Berlin scientist, E. du Bois-Reymond.
9. Thus named by Lavoisier, who recognized it as one of the essential elements of atmospheric air.
10. Londone, 1777. [The Doctrine of Philosophical Necessity, London, 1777; Free Discussions of the Doctrines of Materialism, London, 1778. - Tr.]
11. In a word: How can the one arise from the many?
12. [l cannot find anything in the Disquisitions to prove this statement. What Priestley does say is this: "This argument has been much hackneyed, and much confided in by metaphysicians; but, for my part, I cannot perceive the least force in it," (p. 118.) - Tr.]
13. Albert Lange shares this view. In his History of Materialism, he holds that the above argument hits the weak spot in materialism.
14. There is, indeed, a connecting link between Priestley's system and the reformed dogma: we mean their common opposition to indeterminism. Indeterministic and Pelagian Catholicism offers materialism no such support
15. A curé of Étrépigny in Champagne, died 1733. Testament de J. Meslier, published in 3 vols., with a preface and a biographical introduction, by R. Charles, Amsterdam, 1865.
16. Histoire naturelle de l'âme, The Hague (Paris), 1745; L'Homme-machine, Leyden, 1748; L'Homme-plante, Paris, 1748. Works of La Mettrie, London (Berlin), 1751. [Cf. Lange, History of Materialism.]
17. These "errors" are, in La Mettrie's opinion, nothing but "a trick to make the theologians swallow the poison of mechanism. The animal-machine is Descartes's grandest discovery."
18. Passions de l'âme, I., Art. 16.
19. We found it in Anaximander, Empedocles, Anaxagoras, and Democritus.
20. Born at Paris, 1713; died 1784. The founder of the Encyclopédie (Dictionnaire raisonné des arts, des sciences et des métiers. Par une société de gens de lettres, mis en ordre et publié par M. Diderot, Paris, 1751-1763). His most important philosophical writings are: Pensées sur l'interprétation de la nature, Paris, 1754; Rêve de D'Alembert; Lettre sur les aveugles; Éléments de physiologie. M. Assézat has edited the Complete Works of Diderot from the original editions. He includes what has been published at different periods, and the unpublished manuscripts - preserved in the Hermitage library (Paris, 1875). [On Diderot see the works of K. Rosenkranz (1866) and John Morley (1878, 1886).]
21. 1723-1789. De la nature, 4 vols. 8vo, Amsterdam, 1763-68.
22. A Genevan, 1720-1793. La palingénésie philosophique ou idées sur l'état passé et sur l'état futur des êtres vivants, Geneva, 1769.
23. Claude Adrien, 1715-1771. De l'esprit, Paris, 1758 (anonymous); De I'homme, de ses facultés et de son éducation, London (Amsterdam), 1772 (anonymous) ; Les progrès de la raison dans la recherche de la vérité, London, 1775. Complete works, Amsterdam, 1776 ; Zweibrücken, 1784; Paris, 1794; 1796 (this last edition in 10 vols., 12).
24. Bernard de Mandeville, 1670-1733. The Fable of the Bees, or Private Vices made Public Benefits, London. 1714, 1719.
25. 1717-1783. Author of the masterly Discours préliminaire of the Encyclopedia, which he helped to found. Mélanges de littérature, d'histoire et de philosophic, 5 vols., Paris, 1752.
26. Discours sur les progrès de l'esprit humain, etc- [Complete works by Dupont de Nemours, 4 vols., Paris, 1808-1811.]
27. Esquisse d'un tableau historique des progrès de l'esprit humain (post-humous work), 1794.
28. 1723-1789.
29. In the Mémoires de l'Institut, years IV. and VI. (1796 and 1798); reprinted, Paris, 1802.
30. Closely related to the system of Cabanis is the intellectual or cerebral physiology (known by the name of phrenology) of Gall, Spurzheim and Broussais.
31. De l'esprit des lois. I., ch. I.: Les lois, dans la signification la plus étndue, sont les rapports nécessaires qui dérivent de la nature des choses; et, dans ce sens, tous les êtres ont leurs lois : la divinité a ses lois, etc.
32. See page 399, note 1.
33. 1712-1778. Discours sur l'origine et les fondements de l'inéqalite parmi les hommes, Paris, 1753; Le contrat social, 1762; Émile ou de l'éducation, 1762. [(Euvres, Paris, 1761; 1818-20; 1868. L. Moreau, J. J. Rousseau et le siècle philosophique, Paris, 1870; John Morley, Rousseau, 2 vols., London, 1873. - Tr.]
