ON CHAPTER I.(1) We must distinguish between certainty and truth: there are intimate relations between them, yet they are very different things. Truth is the conformity of the intellect with the object. Certainty is a firm assent to a real or apparent truth.

Certainty is not truth, but it must at least have the illusion of truth. We may be certain of what is false, but not unless we believe it to be true.

There is no truth so long as there is no judgment; for without judgment there is only perception, but no comparison of the idea with the thing; and without comparison there can be neither conformity nor discrepancy. If we conceive a mountain a thousand miles high, we conceive a thing that does not exist; but we do not err so long as we do not assert the existence of the mountain. If we affirm it, there is opposition between our judgment and the reality: this constitutes error. The object of the intellect is truth; therefore, we at least require the illusion of truth in order to be certain: our intellect is weak; hence its certainty is liable to error. The first is a law of the intellect, the second a proof of its frailty.

Philosophy, or, rather, man, cannot rest content with appearances, but demands reality; if any one be convinced that he has only the appearance, or if he even doubt of it, he loses his certainty, for it admits appearances only on condition of their being disguised.

ON CHAPTER II.(2) Even Pyrrho did not doubt of every thing as some pretend; he admitted sensations so far as passive, and resigned himself to the consequences of these impressions, and yielded to the necessity of conforming in practice to what they indicated. No one ever yet denied appearances: it is reality that is disputed; some hold that man must be content with saying it appears; others that he can go so far as to say it is. It is useful to preserve this distinction, as it prevents confusion of ideas in the history of philosophy, and conduces to render clear the question of certainty. Thus of the three questions: is there certainty? on what is it founded? how is it acquired? the first is resolved alike by all the schools, so far as it relates to a fact of our soul: by only admitting appearances, they admit the certainty of them.

ON CHAPTER III.(3) In order to form clear ideas of the development of the understanding, and the other faculties of our soul, the reader may refer to what we advanced in our work, entitled The Criterion, and particularly to the chapters I., II., III., XII., XIII., XIV., XVIII., and XXII.

ON CHAPTER IV.(4) We subjoin the passages from St. Thomas on the unity and multiplicity of ideas, to which we referred in the text. We believe the friends of solid and profound metaphysics will read them with great pleasure.

"In omnibus enim substantiis intellectualibus, invenitur virtus intellectiva per influentiam divini luminis. Quod quidem in primo principio est unum et simplex, et quanto magis creaturÆ intellectuales distant a primo principio, tanto magis dividitur illud lumen, et diversificatur, sicut accidit in lineis a centro egredientibus. Et inde est quod Deus per suam essentiam omnia intelligit: superiores autem intellectualium substantiarum, etsi per plures formas intelligant, tamen intelligunt per pauciores et magis universales et virtuosiores ad comprehensionem rerum propter efficaciam virtutis intellectivÆ, quÆ est in eis. In inferioribus autem sunt formÆ plures et minus universales, et minus efficaces ad comprehensionem rerum, in quantum deficiunt a virtute intellectiva superiorum. Si ergo inferiores substantiÆ haberent formas in illa universalitate, in qua habent superiores, quia non sunt tantÆ efficaciÆ in intelligendo, non acciperent per eas perfectam cognitionem de rebus, sed in quadam communitate, et confusione, quod aliqualiter apparet in hominibus. Nam qui sunt debilioris intellectus, per universales conceptiones magis intelligentium, non accipiunt perfectam cognitionem, nisi eis singula in speciali explicentur. (P. 1ⁿ, Q. 89², A. 1°.)

"Intellectus quanto est altior et perspicacior tanto ex uno potest plura cognoscere. Et quia intellectus divinus est altissimus, per unam simplicem essentiam suam omnia cognoscit; nec est ibi aliqua pluralitas formarum idealium, nisi secundum diversos respectus divinÆ essentiÆ ad res cognitas; sed in intellectu creato multiplicatur secundum rem quod est unum secundum rem in mente divina, ut non possit omnia per unum cognoscere; ita tamen quod quanto intellectus creatus est altior, tanto pauciores habet formas ad plura cognoscenda efficaces. Et hoc est quod Dio. dicit, 12, coe. hier. quod superiores ordines habent scientiam magis universalem in inferioribus. Et in lib. de causis dicitur, quod intelligentiÆ superiores habent formas magis universales; hoc tamen observato, quod in infimis angelis sunt formÆ adhuc universales in tantum, quod per unam formam possunt cognoscere omnia individua unius speciei: ita quod illa species sit propria, uniuscujusque particularium secundum diversos respectus ejus ad particularia, sicut essentia divina efficitur propria similitudo singulorum secundum diversos respectus; sed intellectus humanus qui est ultimus in ordine substantiarum intellectualium habet formas in tantum particulatas quod non potest per unam speciem nisi unum quid cognoscere. Et ideo similitudo speciei existens in intellectu humano non sufficit ad cognoscenda plura singularia; et propter hoc intellectui adjuncti sunt sensus quibus singularia accipiat. (Quodlib. 7, A. 3.)

"Respondeo dicendum, quod ex hoc sunt in rebus aliqua superiora, quod sunt uni primo, quod est Deus, propinquiora et similiora. In Deo autem tota plenitudo intellectualis cognitionis continetur in uno, scilicet in essentia divina, per quam Deus omnia cognoscit. QuÆ quidem intelligibilis plentitudo, in intelligibilibus creaturis inferiori modo et minus simpliciter invenitur. Unde oportet, quod ea quÆ Deus cognoscit per unam, inferiores intellectus cognoscant per multa; et tanto amplius per plura, quanto amplius intellectus inferior fuit. Sic igitur quanto angelus fuerit superior, tanto per pauciores species universitatem intelligibilium apprehendere poterit, et ideo oportet quod ejus formÆ sint universaliores, quasi ad plura se extendentes unaquÆque eorum. Et de hoc, exemplum aliqualiter in nobis perspici potest: sunt enim quidam, qui veritatem intelligibilem capere non possunt; nisi eis particulatim per singula explicatur. Et hoc quidem ex debilitate intellectus eorum contingit. Alii vero qui sunt fortioris intellectus, ex paucis multo capere possunt." (P.1^a, Q. 55^a A. 3°.)

ON CHAPTER V.(5) Here is the idea of Condillac's man-statue explained by himself: "To gain this object we imagined a statue internally organized like ourselves, and animated with a mind deprived of every sort of ideas. We also supposed its exterior composed wholly of marble, to allow it the use of none of its senses, and we reserved to ourselves the liberty to open them at our pleasure to the different impressions of which they are susceptible.

"We thought we ought to commence with smell, because of all the senses this is the one which least contributes to cognitions of the mind. Next we had to examine the others, and after having considered them apart and together, we saw the statue become an animal able to attend to its own preservation.

"The principle that determines the development of its faculties is simple; even sensations contain it; for, all being of necessity either agreeable or the contrary, the statue is interested in enjoying some and shunning others. The reader will now be convinced that this interest suffices to give occasion to the gradations of the will and the understanding. Judgments, reflection, desires, passions, are only sensations variously transformed. This is why it seemed to us useless to suppose the soul to have received immediately from nature all the sensations with which it is endowed. Nature has given us organs which show us by pleasure or pain what we ought to seek or to avoid; but here she stops, and leaves to experience the task of leading us to contract habits, and finish the work she has commenced.

"This object is new, and shows all the simplicity of the ways of the Author of nature. Is it not a thing worthy of our admiration thus to see, from man's sensibility to pleasure or pain, spring up in him ideas, desires, habits, and talents of various kinds?"—Traite des Sensations. Dessein de l'ouvrage.

What we admire in Condillac is not his system, but his candor; and we wonder yet more that, for a time, he should have had numerous followers of his so poor and superficial system. The author proposes the difficulty, that as there is in our soul nothing but transformed sensations, it is strange that brutes, which also have sensations, should not be endowed with the same faculties as man. Can the reader imagine what profound reason the French philosopher assigned? We doubt it very much. It is a curious thought: "the organ of touch is less perfect in brutes, and consequently it cannot be to them an occasional cause of all the operations which we observe in ourselves." He did well to adopt the motto: nec tamen quasi Pythius Apollo!

ON CHAPTER VI.(6) The works of the scholastics are worth reading on these points. Treating of the object of science, they are at once exact and profound. It is not easy to think of any thing concerning the classification of truths not explained or indicated by them.

ON CHAPTER VII.(7) Let us not be thought to judge too severely of the forms adopted by the German philosophers. It is well known how Madame de StaËl speaks of them; but happily we can cite in our favor a more competent judge. Schelling, one of the chiefs of German philosophy, says: "The Germans have so long philosophized among themselves, as to gradually depart more and more, in their thoughts and their words, from what is universally intelligible; and the degree of departure therefrom has almost come at last to be the measure of philosophical ability. Examples are not wanting to us. As families which separate from general society, and live wholly among themselves, among other repulsive singularities, come to use expressions intelligible only to themselves, so is it with the Germans in philosophy; and after vain efforts to spread the Kantian philosophy out of Germany, they renounced the attempt to make themselves intelligible to other nations; they became accustomed to regard themselves as the chosen people of philosophy, forgetting that the primary end of philosophy,—an end often neglected, but not the less to be sought for on that account,—is to gain universal consent, by making themselves universally intelligible. This is not to say that we must judge works of thought like exercises in style; but all philosophy not intelligible to all civilized nations, and accessible in every language, cannot, for this reason alone, be the universal and true philosophy."—Schelling's Judgment of V. Cousin, and the state of French and German Philosophy in general. 1834. p. 4.

Schelling flatters himself that German philosophy is about to take a better course with respect to clearness, and adds: "The philosophical writer who, for tens of years past, was unable to depart from the terms and forms of the school, without loss of his scientific reputation, may hereafter emancipate himself from this restraint. He will seek depth of thought; and an absolute incapacity to express himself with clearness, will no longer be regarded as the mark of talent and philosophical inspiration." We have nothing to add to this passage; we would only remind its author that: mutato nomine, de te fabula narratur.

ON CHAPTER VIII.(8) The perusal of Schelling's work on Ideal Transcendentalism leaves no doubt as to his view of this identity, which at bottom neither is nor can be any thing else than pantheism; yet, for the sake of truth, we will allow that Schelling seems to have modified his doctrine, or to have feared its consequences, if we are to consider the indications found in his discourse at the opening of his course of philosophy, at Berlin, the 13th of November, 1841. We there find the following passage, worthy of the attention of all thinking men: "The difficulties and obstacles of all kinds, against which philosophy contends are visible, and in vain would we attempt to dissemble them. Never was there a more powerful reaction against philosophy on the part of real and active life than at this present epoch; and this proves philosophy to have penetrated even to the vital questions of society, those concerning which no one can rest indifferent. So long as a philosophy is only in the first stages of formation, taking the first steps in its march, no one cares for it, except philosophers themselves; other men await the last word of philosophy, since it is important to the general public only in its results.

"We confess that we ought not to take as the practical result of a solid and profoundly meditated philosophy whatever it may please any body to designate as such: were it so, the world would be subjected to doctrines the most repugnant to sound morality, even such as sap its foundation. No! No one judges of philosophy by the practical conclusions drawn by ignorance or presumption. Moreover, lest deception on this point be possible, the public should reject a philosophy which has such results, without examining or even judging it in its principles; it should say that it cannot understand the depth of these questions, or the artificial and intricate march of the arguments; but without pausing here it should promptly decide that a philosophy leading to such conclusions cannot be true in its principles. What the Roman moralist said of the useful: nihil utile nisi quod honestum, is equally applicable to the investigation of truth: no philosophy that respects itself will allow that it leads to irreligion. Yet actual philosophy is in such a state, that, however much it promises a religious result, no one admits it; for deductions drawn from it convert the dogmas of the Christian religion into a vain phantasmagory.

"As to this, some of its most faithful disciples are openly agreed; be the suspicion well founded or not, its existence suffices, and this opinion is established.

"But active life in the last result is always right; and so philosophy is exposed to great risks. They who war on one philosophy are not far from condemning all philosophy; they say in their heart, there is no longer philosophy in the world. I myself am not exempt from these condemnations, since it is pretended that it is I, who first gave impulse to this philosophy which is at present so badly judged of, because of its religious results.

"How shall I defend myself? Certainly I would never attack a philosophy for its last results; but I would judge it in its first principles, as every philosophical mind should. It is moreover well enough known that I have shown myself little satisfied with the philosophy of which I speak.

"The moral and spiritual worlds are so divided that any point of union for an instant should be a motive of satisfaction. Besides to destroy, is a very sad thing when there is nothing wherewith to replace the thing destroyed. 'Do it better yourself,' we say to one who can do nothing but criticize.

"I therefore consecrate myself entirely to the mission with which I am charged; for you I will live; for you I will labor without ceasing while there remains in me the breath of life, and while He permits me, without whose permission not a hair can fall from our head, and yet less a deeply felt word proceed from our mouth. He, without whose inspiration not one lucid idea can shine on our mind, nor one thought of truth and liberty illumine our soul."

This passage shows the embarrassment of the German philosopher's position, and the irreligious consequences attached to his doctrines. It is consoling to see him pay some homage to truth; but it is afflicting to see him still pretend to save its inconsequence.

ON CHAPTER IX.(9) In these latter days there have not been wanting some to count the illustrious Malebranche among the partisans of pantheism. We cannot conceive how M. Cousin could say; "Malebranche est avec Spinoza le plus grand disciple de Descartes. Comme lui il a tirÉ des principes de leur commun maÎtre les consÉquences que ces principes renfermaient. Malebranche est À la lettre Spinoza chrÉtien." (Fragments Philosophiques. T. 2^me. p. 167. Ed. 3^ieme.) We repeat that we cannot conceive how any one, who had read ever so little of the great metaphysician's works, should assert such a paradox. The slightest glance at his writings suffices to show in them the most lofty spiritualism united with profound respect for the dogmas of our most holy religion. When we treat of the various philosophical systems of the origin of ideas and the problem of the universe, we shall have other occasions to vindicate the wise and pious author of the Investigation de la VeritÉ. Yet we were unwilling to pass by the present occasion without doing him the justice to defend him from imputations, which he would, were he living, repel as intolerable calumnies. Who would have thought when he wrote those works, on every page of which we find, God, the mind, the Christian religion, eternal truth, and original sin, with frequent texts from the sacred Scriptures and St. Augustine, that he would ever be ranked with Spinoza, with the absurd epithet of Christian Spinoza? Such is at times the sad lot of great men, thus to be held as chiefs of sects they abhorred. Malebranche styled Spinoza, l'impie de nos jours, and M. Cousin dares call Malebranche the Christian Spinoza.

ON CHAPTER X.(10) We are not ignorant of the difficulties to which Leibnitz's systems are subject; but it is necessary to show that in this great man's mind the erroneous doctrines of modern Germans had no place. "Et c'est ainsi," he says, in his Monadologie (No. 38), "que la derniÈre raison des choses doit Être dans une substance necessaire, dans laquelle le dÉtail des changmens ne soit qu'eminemment, comme dans la source, et c'est ce que nous appelons Dieu. Or cette substance Étant une raison suffisante de tout ce dÉtail, lequel est aussi liÉ partout, il n'y a qu'un Dieu, et ce Dieu suffit.

"On peut juger aussi que cette substance suprÊme qui est unique, universelle, et necessaire, n'ayant rien hors d'elle qui en soit indÉpendant, et Étant une suite simple de l'Être possible, doit Être incapable de limites et contenir tout autant de realitÉ qu'il est possible.

"D'oÙ il s'ensuit, que Dieu est absolument parfait, la perfection n'Étant autre chose, que la grandeur de la realitÉ positive prise prÉcisÉment en mettant À part les limites ou bornes dans les choses qui en ont. Et lÀ, oÙ il n'y a point de bornes, c'est-À-dire, en Dieu, la perfection est absolument infinie.

"Il s'ensuit aussi que les crÉatures ont leur perfections de l'influence de Dieu, mais qu'elles ont leurs imperfections de leur nature propre, incapable d'Être sans bornes. Car c'est en cela qu'elles sont distinguÉes de Dieu.

"Il est vrai aussi, qu'en Dieu est non seulement la source des existences, mais encore celle des essences, en tant que rÉelles, ou de ce qu'il y a de rÉel dans la possibilitÉ."

In his dissertation on the Platonic philosophy he combats the pantheistic tendencies of Valentine Weigel, in these words: "Valentinum Weigelium, qui non tantum vitam beatam peculiari libero per Deificationem explicat, sed et passim mortem et quietem hujusmodi commendat, vellem cum aliis Quietistis suspicionem similis sententiÆ non dedisse. * * * Spinoza aliter eodem tendebat; ei una substantia est, Deus; creaturÆ ejus modificationes, et figurÆ in cera continue per motum nascentes et pereuntes. Ita ipsi, perinde ut Almerico, anima non superest, nisi per suum esse ideale in Deo ut ibi ab Æterno fuit.

"Sed nihil in Platone animadverto, unde colligam, animos propriam sibi substantiam non servare; quod etiam sane philosophanti extra controversiam est, neque intelligi contraria potest sententia, nisi Deum et animam corporea fingas, neque enim aliter ex Deo animas, tanquam particulas divellas; sed talis de Deo atque anima notio, aliunde absurda est." (Leibnitz. Epist. ad Hanschium de Philos. Platon.)

So far was Leibnitz from deeming the tendency to pantheism an elevated philosophy, that, as we have just seen, he considered it the result of a rude imagination. It is very remarkable that under an historical as under a metaphysical aspect Leibnitz agrees with St. Thomas; both express the same ideas in very similar words. The holy doctor asks if the soul is made from the substance of God, and there takes occasion to examine the origin of the error, and says: "Respondeo dicendum, quod dicere animam esse de substantia Dei, manifestam improbabilitatem continet. Ut enim ex dictis patet, anima humana est quandoque intelligens in potentia, et scientiam quodammodo a rebus acquirit, et habet diversas potentias; quÆ omnia aliena sunt a Dei natura, qui est actus purus, et nihil ab alio accipiens, et nullam in se diversitatem habens, ut supra probatum est.

"Sed hic error principium habuisse videtur ex duabus positionibus antiquorum. Primi enim, qui naturas rerum considerare inceperunt, imaginationem transcendere non valentes, nihil prÆter corpora esse posuerunt. Et ideo Deum dicebant esse quoddam corpus, quod aliorum corporum judicabant esse principium. Et quia animam ponebant esse de natura illius corporis, quod dicebant esse principium, ut dicitur in primo de anima, per consequens sequebatur quod anima esset de substantia Dei. Juxta quam positionem etiam ManichÆi, Deum esse quamdam lucem corpoream existimantes, quandam partem illius lucis animam esse posuerunt corpori alligatam. Secundo vero processum fuit ad hoc quod aliqui aliquid incorporeum esse apprehenderunt; non tamen a corpore separatum, sed corporis formam. Unde et Varro dixit quod Deus est anima, mundum intuitu, vel motu et ratione gubernans: ut Augu. narrat 7 de Civit. Dei. Sic igitur illius totalis animÆ partem, aliqui posuerunt animam hominis: sicut homo est pars totius mundi; non valentes intellectu pertingere ad distinguendos spiritualium substantiarum gradus, nisi secundum distinctiones corporum. HÆc autem sunt omnia impossibilia, ut supra probatum est, unde manifeste falsum est animam esse de substantia Dei." (P. 1^a, Q. 90^a, A. 1^o.)

ON CHAPTER XI.(11) We often find the intellect identified by the scholastics with the thing known, even when they treat of created intellects; but this identity is limited to the purely ideal order, and denotes only the intimate union of the idea and the intellect. It is well known what importance they attached to matters and forms; and this distinction is also applied to the phenomena of intelligence. Although the idea was considered as a thing distinct from the intellect, yet, as the intellect is perfected by it, and placed in relation with the thing represented, they said that the intellect was the same as the thing known. We must thus explain passages in St. Thomas and other scholastics, since, although their expressions, if considered in isolation, would be inexact, they are not so, if regard be had to the meaning which they attributed to them, and which clearly follows from their fundamental principles. Thus St. Thomas (Quodlibet. 7 A. 2), to prove that the created intellect cannot know many things at the same time, says:

"Sed quod intellectus simul intelligat plura intelligibilia, primo et principaliter, est impossibile. Cujus ratio est quia intellectus secundum actum est omnino, id est, perfecte res intellecta: ut dicitur in 3 de anima. Quod quidem intelligendum est non quod essentia intellectus fiat res intellecta vel species ejus; sed quia complete informatur per speciem rei intellectÆ, dum eam actu intelligit. Unde intellectum simul plura intelligere primo, idem est ac si res una simul esset plura. In rebus enim materiabilus videmus quod una res numero non potest esse simul plura in actu, sed plura in potentia.

"Unde patet quod sicut una res materialis non potest esse simul plura actu, ita unus intellectus non potest simul plura intelligere primo. Et hoc est quod Alga, dicit, quod sicut unum corpus non potest simul figurari pluribus figuris; ita unus intellectus non potest simul plura intelligere. Nec potest dici quod intellectus informatur perfecte simul pluribus speciebus intelligibilibus, sicut unum corpus simul informatur figura et colore; quia figura et color non sunt formÆ unius generis, nec in eodem ordine accipiuntur quia non ordinantur ad perficiendum in esse unius rationis; sed omnes formÆ intelligibiles in quantum hujusmodi, sunt unius generis, et in eodem ordine se habent ad intellectum, in quantum perficiunt intellectum in hoc quod est esse intellectum in actu. Unde plures species intelligibiles se habent sicut figurÆ plures, vel plures colores, qui simul in actu in eodem esse non possunt secundum idem."

By the first passage, we see that the meaning of identity of the intellect with the thing known, is the same as explained in the beginning of this note; to wit, the intimate union of the idea of intelligible species with the intellect, as the form with its matter,—a form which perfects the intellect, makes it pass from potentiality to actuality, and places it in relation with the thing represented.

ON CHAPTER XII.(12) The doctrine of immediate intelligibility is susceptible of still further illustration; but as this cannot be clearly done without examining at length the nature of ideas, which does not pertain to our present treatise, we shall reserve it for its proper place.

ON CHAPTER XIII.(13) Enough, perhaps, was not said in the text to enable all readers to form clear and complete ideas of the representation of causality; but this doctrine, as regards the first intelligence, is closely allied to the questions on the foundation of the possibility even of non-existent things,—questions which we cannot here investigate without reversing the order of subjects.

ON CHAPTER XIV.(14) The distinction of geometrical and non-geometrical orders of ideas is of the utmost importance in ideology. We have given this distinction in order that the examination of a truth fundamental among purely ideal truths might not remain incomplete. But its explanation and foundation will be given in our treatise on the of space and extension.

ON CHAPTER XV.(15) The word instinct, when applied to the intellect, is clearly taken in a different sense than it is when applied to irrational animals. It has here no ignoble meaning; and this is in accordance with the use made of it when divine things are spoken of. One meaning given it by the dictionary is, "impulse, or movement of the Holy Ghost, in speaking of supernatural inspirations." The Latin, instinctus, means inspiration. Thus: "Sacro mens instincta furore."

ON CHAPTER XVI.(16) The confusion of ideas upon this point originates in that tendency to unity of which we spoke in our Fourth Chapter. We first suppose there must be one only principle, and we ask what it is; whereas, before inquiring what it is, we should ascertain if there be one only, as is supposed. We have already seen that Fichte's system rested on the same supposition. Thus the cause of innocent disputes in the schools may lead to more transcendental errors.

ON CHAPTER XVII.(17) We have, we think, faithfully interpreted the thought of Descartes, but lest there should be some doubt as to this, we subjoin a notable passage from his answer to the objections collected by PÈre Mersenne from various philosophers and theologians, against the Second, Third, Fourth, Fifth, and Sixth Meditations.

"When we know that we are something that thinks, this first notion is taken from no syllogisms; and when any one says: I think, therefore I am, or exist, he does not infer his existence from thought, as by the force of a syllogism, but as a thing known by itself; he sees it by a simple inspection of the mind; for if he deduced it from a syllogism, he would have to know beforehand this major; whatever thinks, is, or exists. On the contrary, this proposition is manifested to him by his own sentiment that he cannot think without existing. It is a property characteristic of our mind to form general propositions from the knowledge of particular propositions." Descartes does not always explain himself with this clearness; the objections of his adversaries made him examine his doctrine more thoroughly, and this contributed to clear up his ideas.

ON CHAPTER XVIII.(18) To form an accurate estimate of Descartes' views, let us listen to his own explanation of his system.

"As the senses sometimes deceive us, I wished to suppose that nothing of what they make us imagine appeared; as there are men who are deceived, and make paralogisms even when reasoning upon the simplest matters of geometry, I judged myself as liable to err as they are, and I rejected as false all those reasons I had before held to be demonstrations; and also considering that even the thoughts which we have while awake may come to us while asleep, although no one of them may be true, I resolved to feign that all things which had entered my mind contained no more truth than illusory dreams. But I immediately observed that, while I wished to think that every thing was false, it was necessary for me, who thought this, to be something; and, noting that this truth: I think, therefore I am, was so firm and secure, that the most extravagant suppositions could not shake it, I judged that I might, without scruple, receive it as the first truth of philosophy."—Discours sur la MÉthode. P. 4^ieme.

We said that the doubt of Descartes was a supposition, a fiction, and these are the very terms he himself uses. In his reply to the objections of PÈre Mersenne, we find the following confirmatory extract: "I have read with great satisfaction your observations upon my treatise on philosophy, for they show your good-will towards me, your piety towards God, and your zeal for the advance of his glory. I cannot but rejoice that you have judged my arguments worthy of your criticism, but also that you say nothing not easily answerable.

"In the first place, you remind me that I have rejected the ideas of phantasms of bodies, not truly, but only by a mere fiction, in order to conclude that I am something that thinks, fearing, perhaps, that I should believe it followed from this that I am only something that thinks; but I have already shown, in my Second Meditation, that I agreed with this, and I said: 'But these things, which I suppose not to be, because I do not know them, may not really be any thing different from me who know them; of this I can say nothing, I have at present nothing to do with it.'" * * * * * * *

We here see that Descartes did not deny his doubt to be a mere fiction; he even says that he does nothing but apply a method, the necessity of which all philosophers admit.

"I pray you," he continues, "to remember that with respect to matters of the will, I have always made a broad distinction between the contemplation of truth and the uses of life; as regards the latter, I am so far from thinking that we must follow only things very clearly known, that I believe we must not always consider even what is most probable, but that we must, among things wholly unknown or uncertain, sometimes choose one, and hold firmly to it, so long as we see no reason for not doing so, just as if we had chosen it from evident and certain motives, as I have already explained in the Discours sur la MÉthode; but when we treat only of the contemplation of truth, who ever doubted that it was necessary to suspend the judgment upon things that are obscure or not distinctly known?"

In what, then, consists Descartes' merit? In having applied a rule known to all, and employed by few, and in so doing at the very time that prejudices in favor of the Aristotelian doctrine were the strongest. Descartes plainly says so; his method of doubting is not new, only the application of it was wanting; for, as regards its fundamental principle, "who ever doubted that it was necessary to suspend the judgment upon things that are obscure or not distinctly known?"

Understanding Descartes' method in this sense, that is, taking the doubt as a supposition, a mere fiction, it is not opposed to sound religious and moral principles. The profound philosopher does not seem to disdain to set his readers at rest upon this point; he ingenuously shows, in commencing his investigations, that his religious belief was safe. "Finally, as before undertaking to rebuild the house wherein one lives, it is not enough to demolish the old one, and provide materials and workmen, or to exercise one's self in architecture, and to carefully trace the design of the new house; but it is also necessary to have another house in which to live, while the new one is building; so that my actions might not be unresolved, like my judgments, and that I might, in the meantime, live as happily as possible, I made a provision for myself; it consists of three or four maxims. The first is, to observe the laws and customs of my country, and constantly to preserve the religion in which, by the grace of God, I have been instructed from my infancy. * * * * * * After having assured myself of these maxims, and laid them aside with the truths of faith which have always been first in my belief, I judged that I might freely reject the rest of my opinions."—Discours sur la MÉthode, P. 3^ieme.

ON CHAPTER XIX.(19) With respect to the distinction between the testimony of consciousness and that of evidence, as in the analysis of the proposition: I think, therefore I am; there can be no doubt that Descartes did not express himself with sufficient precision and exactness. See, for example, this extract: "After this, I considered in general what is necessary for a proposition to be true and certain; for, although I had not yet met such a one, I nevertheless thought I ought to know in what this certainty consisted; and observing that in the proposition, I think, therefore I am, there is nothing to assure me of its truth, except the clear perception that in order to think I must be, I judged that I could take it to be a general rule that things clearly and distinctly conceived are all true; only there is some difficulty in ascertaining what things we do distinctly conceive."—Discours sur la MÉthode. Partie 4^me.

ON CHAPTER XX.(20) The apodictical certainty of which Kant speaks in the passage cited, is the result of the intrinsic evidence of ideas, or, in other words, it is what the schoolmen called metaphysical certainty.

ON CHAPTER XXI.(21) Besides the questions on the principle of contradiction as the only foundation of certainty, there are others as to its scientific utility and importance. We shall, when we come to treat of the idea of being in general, examine these points at length; wherefore we will now pass them by.

ON CHAPTER XXII.(22) We see by a passage from the fourth part of the Discourse on Method, by Descartes, cited in note xv., that besides the principle, I think, therefore I am, he admitted the principle of the legitimacy of evidence; for, asking what is necessary in order that a proposition may be true and certain, he says, that having remarked that if he was certain of the truth of this proposition (I think, therefore I am), he was so only because he saw it to be so; he believed that he could take it to be a general rule that things known clearly and distinctly are all true. This shows two principles, closely connected, although very unlike, to enter into Descartes' system. The first is the fact of consciousness of thought; the second is the general rule of the legitimacy of the criterion of evidence.

It is also to be remarked that there is here some confusion of ideas, which we have already pointed out. It is not exact to say that the principle, I think, therefore I am, is evident: the evidence relates to the consequence; but there is, properly speaking, no evidence of the act of thought, excepting consciousness. Evidence is a criterion, but not the only one.

ON CHAPTER XXIII.(23) What we have said of the second proposition of this chapter is independent of the mode in which the soul and body exercise their mutual influence. These questions belong elsewhere. This influence is, in every system, a fact attested by experience; and this is all that is needed for what we propose to establish here.

ON CHAPTER XXIV.(24) For the better understanding of what we have said in this chapter on evidence, it will be well to consider what will be advanced in chapters XXVI. to XXXI., inclusive.

ON CHAPTER XXV.(25) What has been said in this chapter shows the truth of what we said in the twenty-fourth chapter, upon the connection of the different criteria, and the necessity of not confining one's self to an exclusive philosophy. Consciousness serves as the basis of the other criteria, as an indispensable fact; but if we deny the others, we also deny consciousness.

ON CHAPTERS XXVI., XXVII., AND XXVIII.(26) Dugald Stewart in his Elements of the Philosophy of the Human Mind, (P. II., C. II., Section 3, §2,) cites a passage from a dissertation printed at Berlin in 1764, which does not appear so unreasonable as he pretends. We subjoin it, because the German philosopher's opinion seems to us the same that we gave in the text.

"Omnes mathematicorum propositiones sunt identicÆ et representantur hac formula, A=A. Sunt veritates identicÆ, sub varia forma expressÆ, imo ipsum quod dicitur contradictionis principium vario modo enuntiatum et involutum; si quidem omnes hujus generis propositiones revera in eo continentur. Secundum nostram autem intelligendi facultatem ea est propositionum differentia, quod quÆdam longa ratiociniorum serie, alia autem breviore via, ad primum omnium principiorum reducantur, et in illud resolvantur. Sic. v. g. propositio 2+2=4 statim huc cedit: 1+1+1+1=1+1+1+1; id est, idem est idem; et, proprie loquendo, hoc modo enuntiari debet,—si contingat adesse vel existere quatuor entia, tum existunt quatuor entia; nam de existentia non agunt geometrÆ, sed ea hypothetice tantum subintelligitur. Inde summa oritur certitudo ratiocinia perspicienti; observat nempe idearum identitatem; et hÆc est evidentia assensum immediate cogens, quam mathematicam aut geometricam vocamus. Mathesi tamen sua natura priva non est et propria; oritur etenim ex identitatis perceptione, quÆ locum habere potest, etiamsi ideÆ non reprÆsentent extensum."

ON CHAPTERS XXX AND XXXI.(27) We have shown that Dugald Stewart had perhaps in view Vico's doctrine; but without wishing to bring against him the charge he brought against his master, Reid, that of resuscitating the doctrines of the Jesuit Buffier, we would, in order that the reader may judge with full knowledge of the cause, subjoin a remarkable extract from the Scotch philosopher, which will show coincidence between some of his doctrines and those of the Neapolitan. Had Stewart read Vico, we are inclined to believe that he would not have complained of the confusion with which various ancient and modern authors have explained this doctrine.

"The peculiarity of that species of evidence which is called demonstrative, and which so remarkably distinguishes our mathematical conclusions from those to which we are led in other branches of science, is a fact which must have arrested the attention of every person who possesses the slightest acquaintance with the elements of geometry. And yet, I am doubtful if a satisfactory account has hitherto been given of the circumstance in which it arises. Mr. Locke tells us, that 'what constitutes a demonstration is intuitive evidence of every step;' and I readily grant, that if in a single step such evidence should fail, the other parts of the demonstration would be of no value. It does not, however, seem to me that it is on this consideration that the demonstrative evidence of the conclusion depends, not even when we add to it another which is much insisted on by Dr. Reid,—that 'in demonstrative evidence our first principles must be intuitively certain.' The inaccuracy of this remark I formerly pointed out when treating of the evidence of axioms; on which occasion I also observed, that the first principles of our reasonings in mathematics are not axioms, but definitions. It is in this last circumstance (I mean the peculiarity of reasoning from definitions) that the true theory of mathematical demonstration is to be found; and I shall accordingly endeavor to explain it at considerable length, and to state some of the more important consequences to which it leads.

"That I may not, however, have the appearance of claiming, in behalf of the following discussion, an undue share of originality, it is necessary for me to remark that the leading idea which it contains has been repeatedly started, and even to a certain length prosecuted, by different writers, ancient as well as modern; but that, in all of them, it has been so blended with collateral considerations, although foreign to the point in question, as to divert the attention both of writer and reader, from that single principle on which the solution of the problem hinges. * * * * * * *

"It was already remarked, in the first chapter of this part, that whereas, in all other sciences, the propositions which we attempt to establish, express facts real or supposed,—in mathematics, the propositions which we demonstrate only assert a connection between certain suppositions and certain consequences. Our reasonings, therefore, in mathematics, are directed to an object essentially different from what we have in view, in any other employment of our intellectual faculties;—not to ascertain truths with respect to actual existences, but to trace the logical filiation of consequences which follow from an assumed hypothesis. If, from this hypothesis, we reason with correctness, nothing, it is manifest, can be wanting to complete the evidence of the result; as this result only asserts a necessary connection between the supposition and the conclusion. In the other sciences, admitting that every ambiguity of language were removed, and that every step of our deductions were rigorously accurate, our conclusions would still be attended with more or less of uncertainty, being ultimately founded on principles which may, or may not, correspond exactly with the fact." (Elements of the Philosophy of the Human Mind. P. II., C. II., S. 3, § 1.)

This is exactly Vico's doctrine of the cause of the difference in the degrees of evidence and certainty; although he makes a general system, in order to explain the problem of intelligence, what the Scotchman only assigns as a fact to show the reason of mathematical evidence. PÈre Buffier (Trait. des prem. VÉritÉs, P. I., C. II.) explains the same thing with great clearness.

We have said that, considering the indefatigable laboriousness which distinguishes the Germans, it would not be strange if they had read the scholastics. In confirmation of this, we notice that Leibnitz urgently recommends the reading of them, and the more modern Germans are not likely to forget the advice of so able an author.

Among various passages of Leibnitz, we select the following extract, because it seems to us rather curious: "Truth is more spread than one would believe; but it is often colored, also often covered over, and even weakened, mutilated, and corrupted by additions which spoil it, or render it less useful. By observing the traces of truth in the ancients, or, to speak more generally, in all who have preceded us, we dig gold from dirt, and draw the diamond from its mine, light from darkness, and this would really be perennis quÆdam Philosophia.

"It may even be said that some progress would be observable in knowledge. The Orientals have great and beautiful ideas of the Divinity; the Greeks added reasoning and a form of science; the Fathers of the Church rejected whatever was bad in Greek philosophy; but the scholastics labored to usefully employ whatever was acceptable in Pagan philosophy. I have frequently said: aurum latere in stercore illo scholastico barbariei, and I wish we could find some one versed in the Irish and Spanish philosophy, to cull from it what is good; I am sure he would find his labor repaid by many and beautiful truths. There was once a Swiss who mathematized scholastically; his works are but little known; although, from what I have seen of them, I should judge them to be profound and worthy of consideration." (Lettre 3^ieme À M. Remond de Montmort.)

Thus speaks Leibnitz, one of the most eminent men of modern times, and of whom Fontenelle said: "He led the van in all the sciences." See, then, if he was wrong in recommending the study of those authors to all desirous of acquiring a profound knowledge of philosophy. This study, setting aside its intrinsic utility, is of great advantage in judging, with knowledge of the cause, a school, which, whatever its worth, occupies a page in the history of the human mind.

ON CHAPTER XXXII.(28)The author to whom I allude (317) is Fenelon, who, under the name of common sense, includes also the criterion of evidence, as may be seen by this extract: "What is common sense? Does it not consist in the first notions which all men have of the same things? This common sense, which always and everywhere is the same, which precedes all examination, and even holds it in ridicule on certain questions, in which one laughs instead of examining; which renders man unable to doubt, no matter how great his efforts may be; this sense which belongs to all men, which only waits to be consulted in order to discover itself and show us the evidence or the absurdity of the question, is not this what I call my ideas? Here, then, are these general ideas or notions which I cannot contradict or examine, but according to which I examine and judge every thing, so that, instead of replying, I laugh when any thing is proposed clearly in opposition to what these immutable ideas represent."—Existence de Dieu, P. II., v. 33.

There is no doubt that Fenelon speaks of evidence in this extract, since, besides using this very term, he refers to immutable ideas; by common sense he understands the general ideas by which we judge of all things, or in other words, the ideas from which evidence proceeds.