It was not merely in the details of the practical arts that Diderot wrote from material acquired at second-hand. The article on the Zend-Avesta is taken from the Annual Register for 1762. The long series of articles on the history of philosophy is in effect a reproduction of what he found in Bayle, in Deslandes, and in Brucker. There are one or two considerable exceptions. Perhaps the most important is under the heading of Spinosa, to which we shall return presently. The article on Hobbisme contains an analysis, evidently made by the writer's own hand, of the bulk of Hobbes's propositions; it is scarcely, however, illuminated by a word of criticism. If we turn to the article on Société, it is true, we find Hobbes's view of the relations between the civil and temporal powers tolerably effectively combated, but even here Diderot hardly does more than arm himself with the weapons of Locke.
Of course, he honestly refers his readers to these sources of wider information.[181] All that we can say of the articles on the history of philosophy is that the series is very complete; that Diderot used his matter with intelligence and the spirit of criticism, and that he often throws in luminous remarks and far-reaching suggestions of his own. This was all that the purpose of his book required. To imitate the laborious literary search of Bayle or of Brucker, and to attempt to compile an independent history of philosophy, would have been to sacrifice the Encyclopædia as a whole, to the superfluous perfection of a minor part. There is only one imperative condition in such a case, namely, that the writer should pass the accepted material through his own mind before reproducing it. With this condition it was impossible for a man of Diderot's indefatigable energy of spirit, not as a rule to comply.
But this rule too had exceptions. There were cases in which he reproduced, as any mere bookmaker might have done, the thought of his authority, without an attempt to make it his own. Of the confusion and inequalities in which Diderot was landed by this method of mingling the thoughts of other people with his own, there is a curious example in the two articles on Philosopher and Philosophy. In the first we have an essentially social and practical description of what the philosopher should be; in the second we have a definition of philosophy, which takes us into the regions most remote from what is social and practical. We soar to the airiest heights of verbal analysis and pure formalism. Nothing can be better, so far as it goes, than the picture of the philosopher. Diderot begins by contrasting him with the crowd of people, and clever people, who insist on passing judgment all day long. "They ignore the scope and limits of the human mind; they think it capable of knowing everything; hence they think it a disgrace not to pronounce judgment, and imagine that intelligence consists in that and nothing else. The philosopher believes that it consists in judging rightly. He is better pleased with himself when he has suspended his faculty of coming to a conclusion, than if he had come to a conclusion without the proper grounds. He prefers to brilliancy the pains of rightly distinguishing his ideas, of finding their true extent and exact connection. He is never so attached to a system as not to feel all the force of the objections to it. Most men are so strongly given over to their opinions that they do not take any trouble to make out those of others. The philosopher, on the other hand, understands what he rejects, with the same breadth and the same accuracy as he understands what he adopts." Then Diderot turns characteristically from the intellectual to the social side. "Our philosopher does not count himself an exile in the world; he does not suppose himself in an enemy's country; he would fain find pleasure with others, and to find it he must give it; he is a worthy man who wishes to please and to make himself useful. The ordinary philosophers who meditate too much, or rather who meditate to wrong purpose, are as surly and arrogant to all the world as great people are to those whom they do not think their equals; they flee men, and men avoid them. But our philosopher who knows how to divide himself between retreat and the commerce of men is full of humanity. Civil society is, so to say, a divinity for him on the earth; he honours it by his probity, by an exact attention to his duties, and by a sincere desire not to be a useless or an embarrassing member of it. The sage has the leaven of order and rule; he is full of the ideas connected with the good of civil society. What experience shows us every day is that the more reason and light people have, the better fitted they are and the more to be relied on for the common intercourse of life."[182]
The transition is startling from this conception of
Philosopher as a very high kind of man of the world, to the definition of Philosophy as "the science of possibles quâ possibles." Diderot's own reflection comes back to us, Combien cette maudite métaphysique fait des fous![183] We are abruptly plunged from a Baconian into a Leibnitzian atmosphere. We should naturally have expected some such account of Philosophy as that it begins with a limitation of the questions to which men can hope for an answer, and ends in an ordered arrangement of the principles of knowledge, with ultimate reference to the conditions of morals and the structure of civil societies. We should naturally have expected to find, what indeed we do find, that the characteristic of the philosopher is to "admit nothing without proof, never to acquiesce in illusory notions; to draw rigorously the dividing lines of the certain, the probable, the doubtful; above all things never to pay himself with mere words." But then these wholesome prescriptions come in an article whose definitions and distribution of philosophy are simply a reproduction from Christian Wolff, and the methods and dialect of Wolff are as essentially alien from the positive spirit of the Encyclopædia as they were from the mystic spirit of Jacobi.
Wolff's place in the philosophical succession of German speculation (1679-1754) is between Leibnitz and Kant, and until Kant came his system was dominant in the country of metaphysics.[184] It is from
Wolff that Diderot borrows and throws unassimilated into the pages of the Encyclopædia propositions so fundamentally incongruous as this, that "among all possibles there must of necessity be a Being subsisting by himself; otherwise there would be possible things, of the possibility of which no account could be given, an assertion that could never be made." It is a curious thing, and it illustrates again the strangely miscellaneous quality of Diderot's compilation, that the very article which begins by this incorporation of the author of a philosophical system expounded in a score of quartos, ends by a vigorous denunciation of the introduction of the systematic spirit into philosophy.
I shall venture to quote a hardy passage from another article (Pyrrhonienne) which some will think a measure of Diderot's philosophical incompetency, and others will think a measure of his good sense. "We will conclude," he says, "for our part that as all in nature is bound together, there is nothing, properly speaking, of which man has perfect, absolute, and complete knowledge, because for that he would need knowledge of all. Now as all is bound together, it inevitably happens that, from discussion to discussion, he must come to something unknown: then in starting again from this unknown point, we shall be justified in pleading against him the ignorance or the obscurity or the uncertainty of the point preceding, and of that preceding this, and so forth, up to the most evident principle. So we must admit a sort of sobriety in the use of reason. When step by step I have brought a man to some evident proposition, I shall cease to dispute. I will listen no longer to a man who goes on to deny the existence of bodies, the rules of logic, the testimony of the senses, the difference between good and evil, true and false, etc. etc. I will turn my back on everybody who tries to lead me away from a simple question, to embark me in discussion as to the nature of matter, of the understanding of thought, and other subjects shoreless and bottomless."[185] Whatever else may be said of this, we have to recognise that it is exactly characteristic of the author. But then why have written on metaphysics at all?
We have mentioned the article on Spinosa. It is characteristic both of the good and the bad sides of Diderot's work. Half of it is merely a reproduction of Bayle's criticisms on Spinosa and his system. The other half consists of original objections propounded by Diderot with marked vigour of thrust against Spinosa, but there is no evidence that he had gone deeper into Spinosa than the first book of the Ethics. There is no certain sign that he had read anything else, or that he had more of that before him than the extracts that were furnished by Bayle. Such treatment of a serious subject hardly conforms to the modern requirements of the literary conscience, for in truth the literary conscience has now turned specialist and shrinks from the encyclopædic. Diderot's objections are, as we have said, pushed with marked energy of speech. "However short away," he says, "you penetrate into the thick darkness in which Spinosa has wrapped himself up, you discover a succession of abysses into which this audacious reasoner has precipitated himself, of propositions either evidently false or evidently doubtful, of arbitrary principles, substituted for natural principles and sensible truths; an abuse of terms taken for the most part in a wrong sense, a mass of deceptive equivocations, a cloud of palpable contradictions." The system is monstrous, it is absurd and ridiculous. It is Spinosa's plausible method that has deceived people; they supposed that one who employed geometry, and proceeded by way of axioms and definitions, must be on the track of truth. They did not see that these axioms were nothing better than very vague and very uncertain propositions; that the definitions were inexact, defective, and bizarre.
We have no space to follow the reasoning by which Diderot supports this scornful estimate of the famous thinker, of whom it can never be settled whether he be pantheist, atheist, akosmist, or God-intoxicated man. He returns to the charge again and again, as if he felt a certain secret uneasiness lest for scorn so loudly expressed he had not brought forward adequate justification. And the reader feels that Diderot has scarcely hit the true line of cleavage that would have enabled him—from his own point of view—to shatter the Spinosist system. He tries various bouts of logic with Spinosa in connection with detached propositions. Thus he deals with Spinosa's third proposition, that, in the case of things that have nothing in common with one another, one cannot be the cause of the other. This proposition, Diderot contends, is false in all moral and occasional causes. The sound of the name of God has nothing in common with the idea of the Creator which that name produces in my mind. A misfortune that overtakes my friend has nothing in common with the grief that I feel in consequence. When I move my arm by an act of will, the movement has nothing in common in its nature with the act of my will; they are very different. I am not a triangle, yet I form the idea of one and I examine its properties. So with the fifth proposition, that there cannot be in the universe two or more substances of the same nature or the same attributes. If Spinosa is only talking of the essence of things or of their definition, what he says is naught; for it can only mean that there cannot be in the universe two different essences having the same essence. Who doubts it? But if Spinosa means that there cannot be an essence which is found in various single objects, in the same way as the essence of triangle is found in the triangle A and the triangle B, then he says what is manifestly untrue. It is not, however, until the last two or three pages that Diderot sets forth his dissent in its widest form.