Part 4

XXII. It is also certain, that from the truths which are established upon experimental evidence, you can deduce no demonstrative reasoning; or at least of that sort, which the logicians call _à priori_. The reason is, because they are evident of themselves, or else are supported by immediate evidence, and are not dependant upon any other thing from whence they are inferred. Therefore, although for example, I at present am convinced that I am desirous of eating such or such a thing, I cannot persuade any other person that I fancy it, by any immediate demonstration; because this is evident to me, not from any principle that is notorious to all mankind, and from whence may be inferred the existence of such a desire; but because the appetite itself, is intimately connected with my spirit, and I feel it so forcibly, that I cannot doubt of its existence: the same thing happens in the cases of those truths, which are established upon immediate metaphysical evidence. If I should be asked, how I know that the whole is greater than one of its parts, I should answer, that I do not know it from any principle from whence it may be inferred, but because the truth, _that the whole is larger than a part_, is so clearly evident to my mind, that it is as incompatible with doubt, as the light of the sun with midnight darkness. If any one should deny to me, the truth of the maxim, that two contradictory propositions cannot be both true at the same time, it would be impossible for me to prove the truth of the maxim, either by arguments deduced _à priori_, or _à posteriori_. The reason is plain, because if I was to argue the point, the most I could do, would be insisting on the manifest contradiction, and asserting the impossibility of the thing, which is the last resource of logical dialect. But observe, when we are got thus far, my adversary, to act consistently with his first caprice, thinks fit to change his ground, and to admit both extremes of the contradiction, and to insist they are both true. Now how, in this case, am I to prove that they cannot be so? Why I can do it by no other means, than by having recourse to the axiom, that it is impossible two contradictory propositions can be both true at the same time. But this is begging the question from the beginning, and proving what is denied, by the same proposition which is the subject of the dispute.

XXIII. The suppositions we have just made, contain all the solutions we are capable of giving, to the above argument. I say then, that I myself, and I say the same of all others, who are in my present situation and circumstances, have experimental Evidence that I am now awake: because the state of wakefulness, which consists, in the intimate and ultimate disposition of the faculties to exercise themselves in proper operations, is an object, which presents itself to my mind, with such clearness, that if I was never so desirous of doing it, I cannot entertain a doubt of my being at present in that state; nor can any other reason be required of me, nor can I give any other, for assenting to this truth; neither can I for my assent to a first principle, give any other than the beforementioned, nor alledge any other, to explain the existence of any reflection, which my soul is at present intent upon.

XXIV. I will not however dissemble, that after this answer is given, there still remains a serious difficulty to surmount, which may be stated in the following manner. The experimental evidence, from whence we deduce this persuasion, is fallacious; because when we sleep and dream, we are under the same persuasion that we are awake, and our senses then represent to us, that we are engaged in actual exercises in such a manner, that if it was at that time to occur to us, to make reflection upon what we were doing, we should conceive, that we had experimental evidence of our speaking, seeing, hearing, &c. Therefore the idea that I now entertain upon reflection, that I have at present experimental evidence of my being at this instant awake, and engaged in study and writing, affords me no absolute certainty that I am not asleep, or that I am actually so employed.

XXV. This is the utmost extent to which the matter of doubting can be carried. But by way of answer to it, I shall reply, that the persuasion we have of being awake when we are dreaming, differs greatly from that we have of being awake, when we actually are so. This last is a clear, firm, determined, invincible persuasion, and such a one, as is required to constitute experimental evidence of the certainty of the fact; which it does in such a manner, that notwithstanding all the reflections we can make, and all the doubts and difficulties we can suggest, our assent to, and persuasion of the truth of it, remains firm and unshaken. On the contrary, when we are dreaming, our reflection is obscure, and the persuasion produced in consequence of it, feeble and wavering; which will evidently appear to be the case, if in the course of our dreaming, it should occur to us to make a doubtful reflection, whether what our imagination represents to us is reality, or only a dream; and the result to a man who was to do this would be, a faint and doubtful determination of whether he actually dreams, or only believes he is dreaming, and he would remain in a state of doubt, whether what his fancy represents to him be real or not. I say in all these cases, his decision of the matter, would not be resolute and firm, but wavering and languid. This doubt of whether I am asleep or not, often occurs to me in dreams, which never fails to produce one of the two following effects, either to certify to me that I am dreaming, or to make me suspend my assent to the fact. And I will venture to assure any one, who shall persist for a few moments, in proposing these doubts to himself when he is dreaming, that he will find the same thing happen to him.

XXVI. We may make use of the same reasoning, if the argument is applied to the deliriums of maniacs. Every man, who after having been deprived of his reason, comes to be restored to his senses, finds a great difference with respect to the persuasions he feels, and the clearness of the opinions he forms in a state of sanity, and those he entertained when he was mad. Mad people seldom make any reflections, either on the state of their mind, or the subject of their madness; and when they do happen to make them, are generally more or less blinded by their apprehensions; of which I myself have known some instances; and it has fallen in my way, by the force of lively representations, first to prevail on some mad people to doubt of the truth of their apprehensions, and afterwards to reason them out of them; among whom there was a nun, who had been exceedingly mad for some years, and whose life was thought to be in danger, although in reality it was not so; and I being called to administer the sacraments to her, was so happy as to reduce her mind to a state of calmness, that rendered her capable of receiving them as a penitent. This I accomplished, by using various reasonings and arguments, tending to undeceive her, and at last was so fortunate as to hit upon one, adapted to the nature of her disease, and the state of her mind, which had its effect: but in doing this, great attention should be had to the tone of the voice, and the energy and vivacity of the looks, and care should be taken, that every action should be such, as is likely to give efficacy and force to the arguments you use, in order that they should make an impression on their minds; great caution should also be used not to irritate them; and by these means, they are often brought to intervals of sense; and although it is true, that they seldom last long, still the gaining an hour of calm reason, is a matter of great importance, as it was in the case of the nun we have just mentioned.

XXVII. The delicacy and curiosity of this subject, has caused me to dwell on it longer than was necessary; for I am so far from apprehending, that the arguments which are used in support of universal scepticism, will prevail with, or have any weight on the world in general, that I do not believe there ever yet was a man, who in reality was convinced by them.

SECT. VI.

XXVIII. The limitations with which rigid scepticism may be mitigated, are innumerable; consequently, scepticism will appear more or less absurd, according to the various exceptions with which it is corrected; but this is a matter of such extent, that to reason upon it with any degree of precision would fill a large volume. I shall therefore proceed to treat of scepticism, as confined within the line of physics, which is the point, to which I proposed at first to restrain my arguments on this subject.

SECT. VII.

XXIX. I have always wondered, and do not yet cease to wonder, at seeing modern philosophers attack scepticism as a physical error, and am much astonished, to find them condemn it in that sense as an error, dangerous to the dogmas of faith. Nor can I comprehend, how such a charge can arise, otherwise, than from gross ignorance or malicious spite; unless it is applied to some sceptic, who from explaining himself loosely, may have given occasion for such an imputation.

XXX. The system of physical scepticism, asserts, that physical and natural things, do not admit of demonstration or scientific certainty, but that they are all matter of opinion; and consequently, that we should not call natural philosophy a science, because strictly speaking it is not one, but rather a habit, or acquired facility, of reasoning with probability upon natural things. We shall understand science in this place, in the sense which Aristotle and the schoolmen understand it, who define it, _to be an evident knowledge of the effect by the cause_. But in our definitions, we shall not exclude experimental certainty, or certain knowledge, acquired by the experience we have had, and the observations we have made, of physical matters; but we shall rather maintain it, as the only method by which we can arrive at attaining truth; although I doubt whether we shall ever attain by it, a discovery of the internal, or intimate nature of things.

XXXI. Neither will we deny, that with respect to physical objects, many propositions may be advanced or supported, which are deducible with infallible certainty from metaphysical principles: as for example from this, _the whole is greater than its part_, is evidently inferred, that a man is bigger than his head; and from this, _being is the effect of operation_, is inferred, that my father existed when he begot me. But these, and other innumerable demonstrations of this sort, afford no physical knowledge whatever; because they do not manifest in any degree, either great or small, the nature of the very entities which are the objects of them. Why do I say manifest the nature of the entities? They do not even display to the understanding, a single truth, which may not be comprehended without their help, by the most rustic man upon earth. So that the syllogistical conclusions upon infallible truths, which the school philosophers so much boast of, do nothing more, than explain by circumlocution and in terms of art, the very things, which may be immediately comprehended, and naturally explained, by any rational man who never studied. Further, how can they call by the name of demonstrations, things which demonstrate nothing? that is, they manifest nothing, but what was manifest without their assistance. A logician will say, thinking he says something to the purpose, that he knows by means of the art of demonstration, that which he could not know artificially without this aid. But I answer, that this artificial knowledge is totally useless, because it neither manifests to me any one truth of which I was before ignorant, nor does it illustrate to me with greater clearness, the things I was before acquainted with; it being certain, that it is as evident and clear to the rustic, and that he assents with as much firmness, that the whole tree is bigger than one of its branches, without the help of artificial logic, as I do, assisted with my whole armory of syllogisms. If a learned person, should undertake to instruct a man who walks well, and with a good grace, by explaining to him all the laws of motion, to step scientifically; and also, by explaining to him the number and use of the muscles, should teach him the application of those laws to every member of his body concerned in that exercise; should not we be apt to say, that besides his taking a very tedious one, he had also taken a very needless trouble, it being certain, that his pupil, after all this pains, would not walk a jot better, if so well as he did before; the cases are similar.

SECT. VIII.

XXXII. The thing then being understood, in the sense we have explained it, the conclusion I draw from the premises is, that science, or scientific certainty is not to be found in physics. Doctor Martinez, in the second volume of his _Medicina Sceptica_, (Convers. 27.) proves this conclusion abundantly, both by the authority of scripture, and by the sentences of many fathers; though as the works of this author are easily to be met with, I shall not here insert the authorities he quotes, but shall content myself with adding to them two very remarkable ones that he has omitted. The first is, that of my father St. Bernard (in Cant. Cantic. Serm. XXXIII.), who when he is speaking of philosophers, says, _Vagi sunt, nulla stabiles certitudine veritatis, semper discentes, et nunquam ad scientiam veritatis pervenientes._ And it is somewhat remarkable, that the Saint says further, philosophers never arrive at attaining a certain knowledge of the very truths they themselves are in search of, and are desirous of teaching to other people: _semper discentes_; and lest some should conclude he spoke of supernatural truths, I thought it necessary to hint here, that these are not the objects of philosophical inquiries. Neither should we suppose, that he spoke of the moral philosophers, because many of these, even including the Gentiles, investigated many truths, that came within the compass of their plan, with intire certainty; and it is evident, that if Aristotle, had written with as much precision upon physics, as he did upon ethics, we needed not to have wished for any thing better.

XXXIII. The second authority, is that of Lactantius Firmianus, an illustrious person, and a venerable member of the church; this great man (Lib. III. Divin. Instit. Cap. iv. v. and vi.) treats largely of the scepticism of Archesilaus, of whom we have spoken before, and after combating and confronting this philosopher effectually on the subject of universal doubt, admits without reserve, that he would have been right, if he had limited his scepticism to matters of physics, because there is not, nor ever can be any science, which will teach mankind, the causes and reasons of natural things: _Quanto faceret sapientius, ac verius, si exceptione facta diceret causas, rationesque duntaxat rerum cælestium, seu naturalium, quia sunt abditæ, nec sciri posse, quia nullus doceat, nec quæri opportere, quia inveniri quærendo non possunt_.

XXXIV. Some of the sceptics themselves prove our conclusion, for they say, that the things appertaining to physics are singular, and that from singular things you cannot derive a science. But this reason does not satisfy me. In the first place, notwithstanding physical things are for the most part singular, they in some instances may cease to be singular. Thus, although every real entity is singular, it may, contemplated metaphysically, depart from its singularity. In fact, the schoolmen together with St. Thomas say, that physics may depart or be separated from their singular, but not from their sensible nature; and that mathematical things, may depart or be separated from their singular and sensible, but not from their intelligible nature; also, that metaphysical ones, may depart or be separated from their singular, sensible, and intelligible. In the next place, the axiom that from singular things you can derive no science, should be understood with some grains of allowance; that is, of such singular things as are particularly necessary to the individual, and are accidental to the species; but from those which appertain or belong to the species, science may be deduced, even when they are connected with the individual. For example. If I know scientifically; that man according to the general received opinion respecting him, is risible, I also know scientifically that Peter is risible, for in the following syllogism; _every man is risible; Peter is a man; and therefore Peter is risible_, is implied the truth of the premises, and the consequence deducible from it is, that it is scientifically evident. Further, if ever a philosopher should arise, who should know with certainty, the specific nature of all material entities, and from that knowledge, should be able to demonstrate all their properties, and the respective operations appertaining to each species, and in virtue of this extraordinary penetration, should be capable of giving reasons _à priori_ for all the phenomena of nature, we should not be able to deny, that such a philosopher possessed physical science, notwithstanding the object of his science, related only to the species, unconnected with individuals. What then remains to be proved, is, that in physics there is to be found no sort of science, or evident knowledge of the matters appertaining merely to physics, abstracted from all other considerations; and truly the dogmatic naturalists, would be very happy, could they be permitted to possess a knowledge that amounts to as much as this; nor would it disturb them, to have it dinned in their ears, that the knowledge of common conceptions is metaphysical, and not physical; for they would tell you, that both physics, and metaphysics, may depart or be separated from their singularity, and that the principal distinction between them is, that the last regards its object with a greater degree of abstraction; that is, as exempt from all matter, and considers only those reasons, which may subsist abstracted from matter, such for example as spiritual entities; on the contrary, physics only contemplate material and corporeal entities; the most sublime of which conceptions, is that which regards the reason of the body, and the lowest, that which is attached to the corporeal part of it. But call this knowledge by what sort of name you will, either physical or metaphysical, the way to bring the matter to a short issue is, to shew that there is not in reality, any such knowledge.

XXXV. And what is more easy to be proved than this? I reason thus; physics contemplate the nature of an entity that has motion, or circulation; this may be considered, either according to the specific, or generative nature of the thing; and I assert, that nothing is known with certainty of the nature of any entity that has motion or circulation, either in one or the other of the before named senses.

XXXVI. And to begin with the specific, who can deny that in this sense, we know nothing of any one entity? I defy all the philosophers to tell me what is the constituent or component physical substance, of any one of the material entities that is to be found in the universe, and will give them leave to chuse that which they have most examined. St. Basil has some words (Epist. 168. _ad Eunomium_) that are admirably applicable to this purpose, and which I shall here insert: _Itaque qui se existentium scientiam assequutum esse gloriatur, exponat nobis quomodo, quod minimum esse eorum, quæ in lucem prodierunt, natura habeat._ Let the presumptuous philosopher, who boasts of his physical knowledge, explain to us the nature of the least entity which God has created. Let him, adds the same Father, who is ostentatiously vain of having penetrated into the secrets of nature, tell us what is the nature of an ant: _Dicat formicarum nobis naturam, qui eorum, quæ in natura sunt scientiam cum fastu se prædicat assequutum._ But why should we waste time? There is not, nor ever was to this day, any one, who by means of acquired science, could penetrate the constituent or component physical substance of any living or inanimate entity; the reach of our capacities not permitting us to go further, than to distinguish by some very extrinsic accidents, one thing from another; and this mode of distinguishing, is confined principally to those we call naturalists, and rarely extends to those in the schools, who acquire the appellation of philosophers, and who generally content themselves with distinguishing some few, which they commonly do in the unhappy manner we shall proceed to point out; but when school philosophers descend to treat of specific conceptions, their philosophy is so miserable and confined, that they only attempt to give the colour of a definition to a few species of brutes, whose voice they describe by some particular name, and then explain their conception of them, by some term derived from that name; thus they call the lion a roaring animal; the dog a barking one, and the horse a neighing one; but the fish, because they are very numerous, and are for the most part mute, cannot well be comprehended within this rule, and therefore are obliged to go without a definition.

XXXVII. The school philosophers cannot be ignorant, that these are not definitions, but should rather be termed mere shadows of definitions, which they make use of for want of true ones, to express logically, what definition is, what species, what gender, what difference, and other things appertaining to logical dialect; but is it not clear, that defining a horse by calling him a neighing animal, can give us no better conception of the creature, than may be conveyed to us by the most stupid clown, who would explain the thing more simply, and without school jargon, by telling us that a horse _is an animal that neighs, or is capable of neighing_? Oh! what a penetrating philosophical description is this of the nature of a horse!