more true upon the internal parts of our bodies. I hope that we shall go beyond conjecture on many occasions, and I already now believe that at least the violent agitation of the parts of the fire of which you just spoke should not be reckoned among the things which are only probable. It is a pity that the hypothesis of Descartes regarding the constitution (contexture) of the parts of the visible universe has been so little confirmed by the re searches and discoveries since made, or that Descartes did not live fifty years later to give us an hypothesis upon the basis of present knowledge as ingenious as the one he gave upon the basis of the knowledge of his time.1 As for the gradual con nection of species, we have said something concerning it in a preceding conference, in which I remarked that philosophers had already reasoned upon the vacuum in the forms or species.2 Everything goes by degrees in nature, and nothing by leaps, and this rule regarding changes is a part of my law of contiimity.3 But the beauty of nature, which desii'es distinct perceptions, demands the appearance of leaps, and so to speak musical ca dences in phenomena, and takes pleasure in mixing the species. Thus although there may be in some other world mediate spe cies between man and beast (according as we understand these words), and although there may be somewhere rational animals surpassing us, nature has found it good to keep them away from us, in order to give us without contradiction the supe riority we have in our globe. I speak of mediate species, and I should not wish to regulate myself here by human individ uals, who approach the brutes, because apparently this is not a defect of faculty, but a hindrance to its exercise; so that I think that the most stupid of men (who is not in a condition contrary to nature by reason of some disease or some other per manent defect taking the place of the disease) is incomparably more rational and more docile than the most spiritual of all 1 Leibnitz here refers to Descartes' theory of vortices, which he elaborated in his Principia Philosophise, Pts. III. and IV. A brief account of it will be found in the Encyclop. Brit.,!>th ed., article "Descartes," Vol. 7, pp. 107-108 (American Reprint). Cf. also J. H. v. Kirchmann's German translation, with notes, of the Prin. Philos. (Vol. 2G, Ft. I., of his Philos. Bibliothek.), 2d ed. Heidelberg, 1887. For other references of Leibnitz to the theory, cf. Ger- hardt, Lribmz. philox. Schrift., 4, 283, 288-289, 340 (Dutens, Leibnit. op. om., CH. xvi] ON HUMAN UNDERSTANDING 553 the beasts, although the contrary is sometimes said by way of a witticism. For the rest, I strongly approve the search for analogies: plants, insects, and the comparative anatomy of animals will furnish them more and more, especially if we continue to avail ourselves of the microscope still more than we have done. And in matters more general you will find that my views concerning.the Monads diffused everywhere, their unending duration, the conservation of the animal with the soul, the perceptions undistinguished in a certain condi tion, such as the death of simple animals, the bodies Avhich it is rational to attribute to genii, the harmony of souls and bodies, which causes each to follow perfectly its own laws without being disturbed by the other and without the necessity of distinguishing therein the voluntary or the involuntary: you will find, I say, that all these views are entirely conformed to the analogy of the things which we observe and which I merely extend beyond our observations, without limiting them to certain portions of matter or to certain kinds of actions, and that the only difference therein is from the great to the small, from the sensible to the insensible.
§ 13. Ph. Yet there is one case where we defer less to the analogy of natural things which experience has made known to us, than to the contrary testimony of a strange fact which is far from it. For when supernatural events are conformed to the ends of him who has the power to change the course of nature, we have no reason for refusing to believe them when well attested, and this is the case of miracles which find not only belief for themselves, but give it also to other truths which need such confirmation.1 § 14. Finally, there is a testi- 1 Leibnitz here takes no notice of this remark of Locke concerning miracles, but expresses himself briefly on the subject in the New Exsayx, Preface, ante, p. 55, and Bk. IV., chaps. 17 ad fin., infra, p. 582, 19 ad fin., infra, p. 606; and more fully in the Theodicee, Discours preliminaire, etc., § 3, Gerhardt, (i, 50, Erdmann, 480, Jacques, 2, 2(5, Janet, 2, 34, Dutens, 1, (15, Pt. I., § 54, Pt. II., §§ 207, 20«S, Pt. III., § 249; Discours de metaphysiquf, 168(5, §§ 7, 16, G. 4, 432, 441; Rcmarques *ur la lettre de M. Arnaud, May 13, 1(580, G. 2, 40; Letters to Clarke, G. 7, 352 *</., E. 74(5 sq., Js. 2, 414 sq., Jt. 2, 617 sq., D. 2, Pt. I., 110 aq., trans. Duncan, 238 *•<?., No. 1, § 4, No. 2, § 12, No. 3, §§ 13-17, No. 4, §§ 33, 40, 42-45, No. 5, §§ 107, 109-113, 115-118; Response aux Objections eontre le St/steme de rharmonie preetablie qui se trouvrnt dans le livre [du P. Francois Lami] de la ConnoiK-mnce de soy-meme, 1709, G. 4, 594, E. 400, D. 2, Pt. I., 100, and the Essay, first printed by Gerhardt, 4, 577-590, referring to the same book, and dated Berlin, Nov. 30, 1702, G. 4, 587; Letter to Tentzel, 1093, Dutens, 5, 401; 004 LEIBNITZ'S CIUTIQUE OF LOCKE [I:K. iv niony which outweighs all other assent, viz. revelation, i.e. the testimony of God, who can neither deceive nor be deceived; and the assent we give to it is called faith, which excludes all doubt as perfectly as the most certain knowledge. But the point is, to be assured that the revelation is divine, and to know that we understand its real sense; otherwise, we are exposed to fanaticism and the errors of a false interpretation. And when the existence and the sense of revelation is only probable, the assent cannot have a greater probability than that found in the proofs. But we shall speak of this still farther.
Tli. Theologians distinguish between the mot ices of credi bility (as they call them), together with the natural assent which must spring from them and which cannot have more probability than these motives, and the supernatural assent, which is an effect of the divine grace. Books have been AnnotatiunculsB subitttnese ad Tohindi libnim, DC Christianismo mystertis carente, written Aug. 8, 1701, Dutens, 5, 146, 148; Letters to Hartsoeker, Feb. 6, 1711, G. 3, 517-518, D.2, Pt. II., 61, Dee. 7, 1711, G. 3, 529; Syxtfina theologi- cuin, written probably c. 1<>8<>, ed. C. Haas, Tubingen, 18<iO, p. 139. (Jf. also the discussions by Pichler, Theol. d. Leibniz, 1,226-237; K. Fischer, Gesch. d. n. Philos., Bd. II., Leibniz, 3d ed., pp. 57:>-57(i; O. Pfleiderer, Relir/ioiix- philosophie, 2d ed., Berlin, 1883, Vol. 1, pp. 90-94, Eng. trans., Vol. 1, pp. 91-93. Leibnitz — whether consistently or not with his philosophical system is fairly open to question — certainly admits the possibility, and upon sutiicient and proper evidence the actuality, of miracles in the sense of personal acts of God in his universe, should a sufficient and proper reason therefor exist in God's mind. Such acts were not violations of law, but consisted simply in the substitution of a higher law for a lower, and the introduction of a new force in accord therewith. Leibnitz justifies his view thus: (1) The laws or order of nature are not metaphysical necessities, but positive truths, resting on the divine choice of the best as governed by the divine wisdom, and therefore amenable to the requirements of that wisdom, the physical always being subject to the moral order and purpose — "Cum uatura rerum niliil alhul sit quam consuetude Dei, ordinarie aut extraordinarie agere reque facile ipsi est, prout sapientia ejus exigit " (Syst. theol. p. 139, ed. Hass, Tub. I860); (2) All these acts were foreseen as possible, and as such included in the original ideal world-plan by the divine intelligence, and therefore involve no change or inconsistency in that plan; cf. Discours de nietaphys., § 7, G. 4, 432: " Or puisque rien ne se pent faire, qui ne soit dans I'ordre, on pent dire que les miracles sont aussi Men dans I'ordre que les operations natufelles, qu'on appclle ainsi parce qu'ellessont conformes a certaines maximes subalt ernes que nous appellons la nature des choses." And he continues in language which would be quoted more appropriately as a parallel passage to that just cited from the Syst. theol.: " Car on pent dire que cette nature n'est qu'une constitute de Dieu, dont il se pent dispenser a cause d'uue raison plus forte, que celle qui 1'a mu a se servir de ces maximes." — TR.
en. xvnj ON HUMAN UNDERSTANDING 555 written expressly on the Analysis of Faith which do not alto gether agree among themselves, but since we shall speak of this in the sequel, I do not wish to anticipate here what we shall have to say in its place.
CHAPTER XVII OF REASON § 1. Ph. Before speaking distinctly of faith, we shall treat of reason. It signifies sometimes clear and true principles, sometimes conclusions deduced from these principles, and some times the cause, and particularly the final cause. Here Ave consider it as a faculty by which man is supposed to be dis tinguished from the beasts and in which it is evident that he much surpasses them. § 2. We need it both to extend our knoidedge * and to regulate our opinion, and it constitutes, properly understood, two faculties, sagacity, for the discovery of mediate ideas, and the faculty of drawing conclusions, or inference. § 3. We may consider in reason these four degrees: (1) the discovery of proofs; (2) their orderly arrangement show ing their connection; (3) the perception of the connection in each part of the deduction; (4) the drawing of the conclusion. We may observe these degrees in mathematical demonstrations.
Th. The reason is the known truth whose connection with another less known makes us give our assent to the latter. But in particular and pre-eminently we call it reason, if it is the cause not only of our judgment, but also of the truth itself, 1 Locke, and in agreement with him here Leibnitz, uses " reason," as Schaarschmidt says, not in the sense of the »oDs of Plato and Aristotle, as the faculty of ideas and first principles, but in the sense of the Greek A6yo;, as the power or faculty of drawing conclusions, thus serving to extend our knowl edge, a process which may be synthetic and deductive as well as analytic and inductive. The function of logic in regulating opinion as opposed to its func tion in extending knowledge is the production of the logical arrangement of knowledge and the classification of concepts, both of which greatly influence the reasoning process and its result, and thereby effect both the extension of knowledge and the regulation of opinion. For a fuller exposition of Locke's view, cf. J. H. v. Kirchmann, Erlauterungen zu J. Locke's Versuch it. d. nwnschl. Verstan'l, No. 4:52, Vol. 52, Pt. II., pp. 105-108, of his Philos. Bibliothek, Berlin, 1874. — TK.
556 LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv which we also call reason a priori, and the cause in things corre sponds to the reason in truths. This is why cause indeed is often called reason, and particularly final cause. Finally, the faculty which perceives this connection of truths, or the faculty of reasoning, is also called reason, and this is the sense you employ here. Now this faculty is really affected by man alone here below, and does not appear in other animals here below; for I have already shown above that the shadow of reason seen in the beasts is only the expectation of a similar event in a case apparently similar to the past, without knowing whether the same reason holds good. Men themselves act no differently in the cases where they are only empirical. But they raise them selves above the beasts, in so far as they see the connections of truths, the connections, I say, which themselves indeed consti tute the necessary and universal truths. These connections are indeed necessary although they produce only an opinion, when after an exact research the prevalence of probability, so far as may be judged, may be demonstrated, so that then there is demonstration, not of the truth of the thing, but of the side prudence requires us to take. In dividing this faculty of reason, I think we do no wrong in recognizing two parts, according to a sufficiently received opinion which distinguishes invention and judgment. As for the four degrees which you remark in mathematical demonstrations, I find that usually the first, viz.: the discovery of proofs, does not appear therein, as is to be desired. There are syntheses, found sometimes with out analysis, and sometimes the analysis has been suppressed. Geometers in their demonstrations put first the proposition which is to be proved, and in order to come to the demonstra tion they set forth by some figure what is given. This is called ecthesis. After this they come to the preparation and draw new lines which they need in the reasoning; and often the greatest art consists in finding this preparation. This done, they con struct the reasoning itself, by drawing inferences from what was given in the ecthesis and from what has been added thereto by the preparation; and employing for this purpose truths already known or demonstrated, they reach the conclusion.
But there are cases where they dispense with the ecthesis and the preparation.
§ 4. Ph. It is generally believed that the syllogism is the en. xvii] ON HUMAN UNDERSTANDING 557 great instrument of reason and the best means of making use of this faculty. For myself I doubt it, for it serves only to show the connection of proofs in one single example and no more; but the mind sees the connection as easily and perhaps better without it. Those who know how to use the figures and the moods most frequently take their use for granted by an implicit faith in their masters without understanding their reason. If the syllogism is necessary, no one knew anything whatever by reason before its invention, and it will be neces sary to say that God having made man a two-legged creature, left it to Aristotle to make him a rational animal; I mean from that small number of men that he could induce to examine the 'grounds of syllogisms, where among more than sixty ways of forming the three propositions there are only about fourteen of them valid. But God has been much kinder to men; he has given them a mind capable of reasoning. I do not say this to lower Aristotle, whom I regard as one of the greatest men of antiquity, whom few have equalled in extent, subtility, pene tration of mind, and strength of judgment, and who by the very fact that he has invented this brief system of the forms of argumentation has rendered a great service to savants against those who are not ashamed to deny everything. But yet these forms are not the only nor the best means of reasoning; and Aristotle did not find them by means of the forms themselves, but by the original way of the manifest agreement of ideas; and the knowledge acquired of them in the natural order in mathematical demonstrations appears better without the aid of any syllogism. To infer is to draw a proposition as true from another already advanced as true, by supposing a certain connection of mediate ideas; for example, from the proposition that men will be punished in another world, we infer that they can determine themselves here. Here is the connection: Men will be punished and God is the one who punishes; therefore punishment is just; therefore the punished is guilty; therefore he could have done otherwise; therefore he is free; therefore finally he has the power of self-determination. The connection is seen better here than if there were five or six involved syllogisms, in which the ideas would be transposed, repeated, and enshrined in artificial forms. The question is to know what connection a mediate idea has with the extremes in a 558 LEIBNITZ'S CRITIQUE OF LOCKE [BK. iv syllogism; but this is what no syllogism can show. It is the mind which can perceive these ideas so placed by a kind of juxtaposition, and that too by its own view. Of what use then is the syllogism? It is of use in the schools where men are not ashamed to deny the agreement of ideas which plainly agree. Whence it comes that men never make syllogisms in their own inquiries after truth or in their teaching of those who sincerely desire to know it. It is quite plain, also, that this order is the more natural: — man — animal — alive; i.e. man is an animal, an animal is alive, therefore man is alive, than that of the syllogism: — animal — alive, man — animal, man — alive; i.e. the animal is alive, man is an animal, therefore man is alive. It is true that syllogisms may be of use in discovering a fallacy concealed under the brilliant splendor of an ornament borrowed from rhetoric, and I had sometimes thought that the syllogism was necessary, at least to guard against sophisms disguised under florid discourse; but after a more severe examination, I have found that we have only to distinguish the ideas upon which the conclusion depends from those which are superfluous, and to arrange them in a natural order to show their incoherence. I knew a man to whom the rules of the syllogism were wholly unknown, who perceived at once the weakness and false reasoning of a long artificial and plausible discourse with which others better skilled in all the finesse of logic suffered themselves to be entrapped; and I believe that there will be few of my readers who do not know such persons. If that were not so, princes in matters relating to their crown and dignity would not fail to introduce syllogisms into the most important discussions, where, however, everybody believes it would be a ridiculous thing to make use of them. In Asia, Africa, and America, among peoples independent of the Euro peans, scarcely any one has ever been heard to speak of them.
Finally, it is found after all that these scholastic forms are not less liable to error; people also are rarely reduced to silence by this scholastic method and still more rarely convinced and won. They will recognize at most that their adversary is more CH. xvn] ON HUMAN UNDERSTANDING 559 adroit, but they do not cease to be persuaded of the justice of their cause. And if fallacies may be involved in the syllogism, the fallacy must be discovered by some other means than that of the syllogism. Yet I am not of the opinion that syllogisms are to be rejected or that we are to deprive ourselves of any means capable of aiding the understanding. There are eyes which need spectacles; but those who use them should not say that no one can see well without spectacles. This would be lowering nature in favor of an art, to which they are perhaps debtors. Unless it may have happened to them wholly con trary to the experience of persons who have availed themselves too much or too soon of spectacles, so that they have so thor oughly obscured their sight by means of them that they are no longer able to see without their aid.
Tli. Your reasoning on the little use of syllogisms is full of a number of solid and fine remarks, and it must be admitted that the scholastic form of syllogisms is little employed in the world and that it would be too long and perplexing if one desired to employ it seriously. And yet, would you believe it, I consider the invention of the form of syllogisms one of the most beautiful, and also one of the most important, made by the human mind.1 It is a species of universal mathematics whose importance is not sufficiently known; and it may be said that an infallible art is therein contained, provided we know and can use it, which is not always allowed. Now you must know that by arguments in form, I mean not merely this scholastic mode of argument used in colleges, but all reasoning which concludes by the force of the form, and in which there is no need of supplying anything, so that a sorites, another syllogistic series which avoids repetition, even an account well drawn up, and algebraic calculation, an infinitesimal analysis, will be for me almost arguments in form, because their form of reasoning has been predemonstrated, so that we are certain not to be deceived thereby. The demonstrations of Euclid most fre quently come near being arguments in form; for when he apparently produces enthymemes, the proposition suppressed and seemingly lacking is supplied by the citation on the mar gin where is given the means of finding it already demonstrated; 1 Cf. ante, p. 379, note 2. The letter to G. Wagner is Leibnitz's most com plete expression of his estimate of the worth of formal logic. — TK.
5GO LEIBNITZ'S CRITIQUE OF LOCKE [UK. iv tliis gives a great abstract without taking anything from its force. These inversions, compositions, and divisions of reasons which he makes use of are only the species of forms of argu mentation peculiar and characteristic of the mathematicians and to the matter they treat; and they demonstrate these forms with the aid of the universal forms of logic. Further, you must know that there are good asyllogistic conclusions which also cannot be rigorously demonstrated by any syllogism without changing somewhat its terms; and this change itself of terms makes the conclusion asyllogistic. There are several of these, as among others, a recto ad obliqnum; for example, Jesus Christ is God; therefore the mother of Jesus Christ is the mother of God. Again, that which clever logicians have called inversion of relation, as, for example, this conclusion: if David is the father of Solomon, without doubt Solomon is the son of David. These conclusions do not cease to be demonstrable by the truths on which the common syllogisms themselves depend. Syllo gisms also are not merely categorical, but also hypothetical, in which are comprised the disjunctives. And we may say that the categorical are simple or complex. The simple categoricals are those which are usually reckoned, i.e. according to the moods of the figures; and I have found that the four figures have each six moods, so that there are twenty-four moods in all. The four common moods of the first figure are only the result of the meaning of the signs, All, No, Some. And the two which I add to them in order to omit nothing are only the subalterns of the universal propositions. For of these two ordinary moods, All B is C, and all A is 13, therefore all A is C; again, No B is C, All A is B, then no A is C, we make these two additional moods, All 13 is C, All A is B, then some A is C; again, No B is C, All A is B, then some A is not C. For it is not necessary to demonstrate the subaltern and to prove its conclusions: All A is C, then some A is C; again, No A is C, then some A is not C, although AVC may, however, demonstrate it by the identicals joined with the moods already received of the first figure, in this way: All A is C, Some A is A, then some A is C; again, No A is C, Some A is A, then some A is not C. So that the two additional moods of the first figure are demonstrated by the first two ordinary moods of the said figure with the intervention of the subaltern, itself demonstrable by CH. xvu] ON HUMAN UNDERSTANDING 661