Part 3

IV. And although authors commonly represent to us, some subtil philosophers of antiquity, as obstinately persisting in suspending their assent to every thing that was proposed to them, and which was evident both to their reason, and their senses, and likewise represent them, as earned defenders of universal scepticism, to which opinion they refuse to admit of the least exception; yet for all this, it is very doubtful to me, whether these were their real sentiments; and I am rather inclined to think, they did it, to shew their ingenuity, and to display their talent for disputing; or that from some other motive, they spoke differently from what they thought. The most famous among this tribe, were Archesilaus, Carneades, and Pyrrho. But the first, if we believe Sextus Empericus, was in reality a Platonist, and only a sceptic in appearance; whose method it was, always to dispute problematically upon every thing in public, but was ever careful to suggest in private, to such of his disciples as he found were the most capable, the Platonic doctrine. Cicero says, that his zeal for contesting every thing that was advanced by his school-fellow and rival Zeno, carried him to the dangerous extreme, of endeavouring, although it was against the conviction of his own mind, to refute whatever was advanced by Zeno. We may add to this, that according to the testimony of Diogenes Laertius, Archesilaus never went to the extreme of doubting the evidence of his senses, but rather treated with contempt and derision, those who carried scepticism to that length.

V. Carneades was a most subtil philosopher, and so eminent as an orator, that Cicero in various parts of his works speaks of him with admiration and envy; and assures us, that by the keenness of his ingenuity, and the fertile torrent of his elocution, he could persuade his hearers to believe whatever he thought fit, and Quintilian, and Numenius, declare the same; and it is probable, that his propensity for disputation, and his ambition of shewing his ingenuity, excited him to contest the most established axioms; which together with his affecting to distrust the evidence of his senses, made him pass for a rigorous sceptic. But we may venture to assert, that if an historical anecdote which is related of him by Numenius is to be credited, Carneades believed his eyes as much as any man living; for having surprized a concubine of his in the embraces of his beloved disciple Mentor, he was so offended at his treachery, that he broke with him for ever, and excluded him from being the successor to his academy. How happened it then, that like a good sceptic, he did not doubt whether the representation of that obscenity, might not be a _deceptio visus_? I for my own part am inclined to think, that there never yet was a sceptic in the world, who after the exhibition of such evidence, could maintain his heart and his mind in a state of suspence.

VI. It is commonly said of Pyrrho, who was by so much the most famous of all the sceptics, that he in a manner obscured the others, by giving his name to the system of universal doubt, which at this day is called Pyrrhonism, and the sectaries of it Pyrrhonists; and he was so positive in maintaining, that we should suspend our opinion, with respect to all we saw, or felt, that he would not turn the least aside, to avoid being run over by a mad horse, or bit by a mad dog; nor would he slacken his pace, although he was warned that he was advancing near the edge of a precipice; and that he would have perished a thousand times by these dangers, if his friends, who were attentive to his safety, had not prevented his running headlong into them. But although this account of him is much vulgarized, I do not know whether any other antient author, except Antigonus Carystius, a Greek historian, who was contemporary with, or lived very nearly in the days of Pyrrho, has vouched the truth of it; at least the learned La Mothe de la Vayer, quotes him as the only author, who attests the relation; and it is even doubtful whether Antigonus Carystius asserts the thing positively, because in the _Præparat. Evang. lib. 14. cap. 18._ of Eusebius, we find this author quoted for a fact, which contradicts that relation; which is, that Pyrrho, when a dog was once about to run at him, climbed up a tree to get out of his way, and avoid the danger. Upon which occasion, those who were present, raillied him upon the difference there was between his doctrine and his practice.

VII. But let Antigonus Carystius, who is an author I have not seen, or any other whatever, say what they will, to give sanction to this relation, we may without the apprehension of being accused of injustice, condemn as incredible, the account of Pyrrho’s having carried his extravagance to such a length. This philosopher lived to the age of ninety, and through the whole course of so long a life, it is not probable, he should always have friends at his elbow, ready to save him from the many dangers, to which a man of so rash a conduct must unavoidably have been very frequently exposed, and especially, in the long voyage he made to India to consult the Gymnosophists. Diogenes Laertius, who is the person that gives us the account of the great age to which Pyrrho lived, and of his voyage to India, assures us, that Pyrrho led a very solitary and retired life, which is not very compatible with his having always been attended by his friends, nor is it reasonable to conclude, that a man who was so very ridiculous as he is described to have been, could have very many, or very sincere ones. Finally, the citizens of Elis, his countrymen, elected him the high priest of their religion. Now how is it credible, that they should have confided such an employment to a person, who if his scepticism had been carried to the length we have mentioned, they must certainly have looked upon as a mad man? From this circumstance, it may also be inferred, that the charge of impiety, which was generally imputed to him, was an unjust one; because his countrymen would hardly have elected him the supreme minister of their religion, if they had known that he professed to be of no religion at all, and that he doubted the existence of a deity. What devotion or zeal could they expect for the service of the temple, from a man, who either was ignorant of, or doubted whether the object of their worship existed?

SECT. III.

VIII. I not only think, that these philosophers did not in their hearts, adopt the system of universal doubt; but I also believe, there never was any one who sincerely did it; because there are objects, with respect to which, there can be no doubt but by implication. No one, for example, can doubt of his own existence. The very act of doubting, is affirmative of a certain knowledge, because he who doubts, must certainly be convinced that he does doubt; and if the sceptics are not certain that they doubt, how can they affirm they do with such obstinacy and stiffness? Therefore we should conclude, that it is not from sentiment, but from their fondness for disputation, that some of them defend the system of universal scepticism; and if there ever was any one who truly assented to it, we should not consider him as a philosopher, but as a lunatic; for it would be improper to call maintaining such a system, a particular mode of philosophizing, as we ought with more justice, to term it a particular mode of raving.

IX. It is most likely then, that the most rigid sceptics, and those who were truly and _bona fide_ such, admitted of some exceptions to the universality of their system, or understood it in some determined sense, which limited or restrained it. Socrates, whom some look upon as the primitive father of the sceptics, said of himself, that he knew nothing with certainty, except it was his ignorance of all things. This however, was placing some sort of limitation to the system, although it was but a very small one. But I am of opinion, that Socrates, who was a very modest man, only meant to say, that what he knew amounted to but a small matter, and that therefore we ought to understand his declaring himself totally ignorant, as an hyperbolical expression. Saint Justin the martyr, and other fathers who highly applauded that philosopher, would not have done it, if they had taken him for a rigid sceptic, which would have amounted to the same, as his having been an impious man; because it is evident, that he who doubts of every thing, cannot be a person of any religious principles; but he was so far from such a kind of man, that it is most probable, the Athenians condemned him to death, because he affirmed the existence of one only God. It is at least certain, that he treated the multifarious number of the heathen gods with great derision; from whence we should conclude, that he knew this important truth, that the Godhead admits of no multiplication.

X. Other sceptics, who said that they doubted of every thing, and that we ought to doubt of every thing, did not perhaps mean to exclude all certainty, but only scientific and demonstrative certainty, which except in mathematical cases, we must confess is very rare to be found. Even many mathematical demonstrations, and especially those which are very complicated, are not exempt from the suspicion, of there being some occult fallacy contained in them, on which account they ceased to be true demonstrations. How many have presumed to demonstrate they could square the circle, whose modes of doing it, and their reasonings upon the subject, when they came to be submitted to rigorous examination, have been found to have some sophism involved in them, or to have been built upon some supposition which was taken for certain, when in reality it was not so. The geometrical demonstrations, with which they prove the infinite divisibility of the continued quantity, are sufficiently simple; notwithstanding which, there are authors, who because the infinite divisibility of the quantity is imperceptible, suspect, that there is some occult sophistry involved in those demonstrations.

XI. Others have refused to credit the evidence of their senses; but not so grossly, but that they have condescended to make use of them to direct their actions in the common affairs of civil and human life. They govern themselves by them for the purpose of living, but not for that of philosophizing. The information of their senses serves them to chuse the useful, and avoid the pernicious, but not to determine the theory of an object.

XII. The arguments they assign for this distrust of their senses in the last instance, may be reduced to three. The first is, the distinction we should admit between the impression which objects make on our senses, and the absolute essence or quality contained in the objects themselves. For example, we say that hemlock is bitter. If by this expression, we mean to declare, that this herb makes on our palate a determined impression or sensation, which we call bitterness, we speak properly; but if we mean to say that the herb in itself contains an absolute quality, which we describe by the same name, we speak improperly; for if this was the case, all the animals who relish hemlock would find it bitter; but it happens otherwise, for the goats are fond of it, and eat it greedily. In the same manner do all those reason, who adopt this mode of arguing with respect to all other sensible species. They say, the fire produces in us that kind of impression, which we call heat; but that we ought not from thence to conclude, that it is hot in itself. Thus although by approaching very near to it, it produces pain in us, still it is not sensible of any itself. Therefore we ought not for this reason, to say the fire contains pain, it being at most only capable of occasioning pain; neither ought we to call it hot, but only capable of producing heat; nor can we call it hot but by equivocation, as we say, Medicine is healthy, because it produces health in the animal.

XIII. This distinction is the fundamental maxim, by which the modern philosophers maintain their rejection of all the sensible qualities, which are assigned by Aristotle and his followers to objects; and they carry the matter so far, that they will positively assert to you, that neither snow is white, nor charcoal black, nor a bell sonorous, nor a flower fragrant; and if you mean to express by these denominations, intrinsic qualities, or such as proceed from some accidental intrinsic form contained in objects; they will not allow such descriptions of things to be good and valid, but only so far as they signify certain determined impressions, which by means of the physical and corporeal impulse of the insensible particles of matter, are made on our organs, which are of the same use to us, to enable us to chuse the good, and avoid the pernicious, as our knowledge of the real intrinsic forms would be. They proceed to assert, that men would equally abstain from eating arsenic, if they believed the moderns, who say this mineral kills by dissolving the blood, by the rapid motion of its particles; as they would by believing Aristotle, who imputes all the mischief it occasions to be the effect of a venomous quality existing in the arsenic, and that they would be equally anxious to acquire gold, by believing the moderns, who say its brilliant yellow hue is the effect of a determined impression made by the light on the retina, where it appears reflected in that colour, from the particular texture of the insensible particles of the gold, as they would, by believing Aristotle, who says, the colour proceeds from an accidental form, inherent in the gold itself. I know very well, that a learned philosopher said, a little while ago, that the ladies had great reason to complain of Descartes, for having taken from their faces that delicate smooth whiteness which makes them look so tempting, and for having placed it in their admirer’s eyes. But although this may do very well as a joke, it is certain, that the charm has an equal effect to make them appear desirable, whether it is stamped on the eyes, by the particular reflection, which, by the determined texture of the insensible particles of the skin, is made by the light, or whether it is produced by the intrinsic quality, which the Aristotelicans assign as the cause of colours; and I much doubt, whether to this day, the Carthesian philosophy has served any man as a preservative, against the venom of that sweet poison, which we call beauty.

SECT. IV.

XIV. The second reason assigned for distrusting the evidence of our senses, is the experience we have of the alterations which are produced on sensible species, either by the interposition of a medium, or the different dispositions of our organs. The species, which by passing through a uniform, or homogeneous medium, appears straight, by being passed through a different one, will seem crooked, as may be evinced by passing a straight wand from the air through water, which, by virtue of the refraction of rays produced in its passage from one element to the other, will make it appear crooked. To him who has a jaundice, every thing he looks at seems yellow; and although it is true, that this is the effect of a preternatural accident, we are not certain, whether abstracted from all morbific dispositions, there are not in various individuals, different temperaments and configuration of parts, which are capable of producing different sensations with respect to the same object; and it seems most probable, from all that is evident and manifest to our observation and experience, that the thing is so, for we don’t see any one individual, who is perfectly and exactly like another; and we have known men, whose right eyes have represented objects, both with respect to colour and magnitude, different from their left.

SECT. V.

XV. The third ground for the said distrust, is derived from the erroneous representation of things made by the imaginary faculty, which fancies external sensations of objects that do not exist. Such, for example, as the imagination of him who has had a leg cut off, representing to him a pain in the leg or foot that has been amputated; or that of an hypocondriac person, who fancies himself to be glass, earthen ware, a wolf, or a dog, whose imagination represents those strange forms, as evidently and manifestly palpable to his senses; so that he who fancies himself glass, will swear with invincible firmness, that he perceives in his own person the transparency, and feels on his own skin the smooth surface, which is proper and peculiar to that artificial composition.

XVI. This error is common to all men in their wanderings when they are asleep; because he who dreams, believes he perceives those objects with his senses, which he only perceives with his imagination; and from hence, the rigid sceptics deduce a most pernicious argument, by way of proving, that we should doubt of every thing; because they say no man can be positively certain, whether he is asleep or awake; according to which mode of reasoning, no one can be certain, whether he sees, hears, or touches any thing whatever; for notwithstanding his having the greatest confidence that he is awake, it is possible that he may be sleeping; and that the things which are represented to him as seen, heard, &c. are all imaginary. For example, I consider myself as now writing, and reading what I write. But what certainty have I that I am writing and reading? Have not I dreamed a thousand times, that I was reading and writing? And at those times, such occupations appeared to me, not as things that I was dreaming of, but as exercises that I was really and actually practising; and therefore, that may be the case with me at present.

XVII. I have said already, and with reason, that this argument is a most pernicious and dangerous one; for whatever answer you make to it, your adversary turns upon you, and urges the opposite opinion as forcibly, as you can support your reply. At least I have never seen any solution of this matter, which could more or less vanquish the force of the difficulty. It has been objected to this sort of reasoning, that the argument proves too much, and tends to involve in, and reduce to the same state of doubt, all the sacred dogmas of religion. This remark is a just one, for he who comes to doubt, whether all he hears or sees is not a mere imaginary representation, must necessarily doubt of the reality of all the instruction he has received, both with respect to religion, and every other matter. But what advantage shall we gain, by insisting upon this against a sceptic, whose intention perhaps is to destroy all religion? And although he should not argue with this depraved view, but should reply to these objections out of wantonness, or from motives of vanity and ostentation, and a fondness of shewing his parts, it would be wasting time to dispute with him, or to press the argument, because these instances, notwithstanding they are good ones and may be fairly insisted on, are not answers.

XVIII. It is certain there are some truths, that maugre the clearness and confidence with which the understanding assents to them, are not exempt from being exposed to difficult objections; or to speak more properly, there is no truth whatever, be it ever so firmly established, against which, some sophistical objection may not be raised. It would therefore not be right upon all occasions, to give up a maxim, whose truth we clearly perceive and are convinced of, only because we can’t reply to every argument that may be urged against it. There are truths of such a nature, that although they would strike, and be clear to any man of ordinary understanding, still, the giving an answer to every objection that could be raised against them, might possibly be found a difficult task to a person of very subtil ingenuity. And notwithstanding we should not be able to hit upon an argument, that would confront or silence those which are used by the sceptics, to persuade us to doubt whether we are sleeping or waking, we should not abandon ourselves to such a doubt, but support ourselves in a firm confidence, that we are not mistaken with respect to the state we are in. And in truth, the arguments used to make us doubt of it, are not of such a nature, as that a clear, solid, and unembarrassed answer may not be given to them.

XIX. And in order to do this, I shall begin with supposing, that evidence in this case may be of two sorts, mediate, and immediate. An evident proposition, supported by immediate evidence, is, when without the assistance of any kind of proof, it presents itself so clearly to our understandings, that the mind is constrained by invincible necessity to assent to it. An evident proposition supported by mediate evidence, is, when of itself, it is not represented to our understandings with all this clearness, but is necessarily inferred from some other self-evident proposition.

XX. I will suppose, secondly, that immediate evidence should be divided, into metaphysical and experimental. The first is governed by universal principles, which of themselves persuade or convince the understanding; such as these, the whole is greater than a part; two contradictory propositions can’t be both true at one and the same time. Experimental evidence is derived from certain singular truths, which strike every individual with infallible conviction; such as these, that I at present have such or such a desire, or that I think of such or such a thing, that I suffer some pain, or that I am affected with some particular sensation; for example, joy, sadness, or anger.

XXI. That every individual feels this experimental evidence in some particular instances, no one can doubt, and even if any person, by giving to his scepticism all imaginable extension, should be desirous of doubting of every thing, he could never stifle the experimental evidence that he doubted. And here I can’t help remarking, that experimental evidence is a thing of such moment to the Carthesians, that all their metaphysical testimonies depend on, or are derived from it; because, from that first maxim or proposition, I think, is inferred immediately, the proof of their own existence; and mediately, all the other demonstrable truths, are established upon experimental evidence only.