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ideas of going to London Bridge, and the man's right to know the way, but can find no connexion or agreement between them, and consequently is ignorant of what I mean. He applies to me, therefore, for the intermediate idea by the question,“ Why so ?" and I give it to him by answering, “ Because he has repeatedly been the same road before:” and although he does not put the three ideas into the measured form of the schools, which is called a syllogism, every one as regularly passes through his mind, and gives him the same satisfactory information as if they were to assume such order; in which case they would perhaps run as follows:
Every man who goes repeatedly the same road should know his way;
It would be absurd to introduce this part of logical analysis into common discourse : but it is of high use in the closet, as teaching us precision, by compelling us to measure the force and value of every idea and word of which a proposition consists. We are indebted to Aristotle for its invention : and though it was at one time carried to an absurd excess, it has of late years been far too generally discontinued.
The connective or intermediate idea is not always expressed either in speaking or writing; and hence is not always obvious to the hearer or reader, though it is, or ought to be, so to the framer of the argument. Let me exercise the ingenuity of the audience before me by throwing out as a trial, the following well-known sentiment of Mr. Pope
Who governs freemen should himself be free.
Here are two distinct propositions; and Dr. Johnson, not immediately perceiving their agreement, nor immediately hitting upon any intervening idea or proposition by which they might be united, declared the whole to be a riddle, and that the poet might just as well have written,
Who drives fat oxen should himself be fat.
Had Johnson, however, lived in our own day, and turned his attention to the Continent, it would have been a riddle to him no longer; for he would have
а called to mind, as I doubt not every one before me has done already, the mischief that has happened to many a free people on the Continent, from the unfortunate want of freedom in the sovereign who is placed over them, and his being under the detestable control of one of the worst, and, unluckily, one of the most universal, tyrants the world has ever witnessed.* He would have been, as every one before me must
be, at once prepared to have connected the two ideas of freemen,—and the propriety of their being governed by a free sovereign, by means of a third or intervening idea to this effect, that otherwise the people themselves might run no small risk of having their freedom destroyed by foreign force; the whole of which might assume the following appearance if reduced to the form of a syllogism :
Who governs freemen should be able to maintain their freedom:
Who governs freemen should himself be free.
PROPER OS REAL KNOWLEDGE, then, is of two kinds or degrees, INTUITION and DEMONSTRATION; below which, all the information we possess is imperfect knowledge or OPINION. Mr. Locke, nevertheless, out of courtesy to the Car tesian hypothesis, rather than from any other cause, makes proper or rea
* Napoleon Buonaparte. This lecture was delivered in 1814.
knowledge to consist of three degrees, placing sensible knowledge, or that obtained by an exercise of the external senses, below the two degrees of intuition and demonstration, though above the authority of opinion. In most instances, however, the ideas we obtain from the senses are as clear and as identic as those obtained from any other source: and in all such cases the knowledge they produce is self-evident or intuitive. And although, at times, the idea excited by a single sense may not be perfectly clear, yet, as we usually correct it, or destroy the doubt which accompanies it, by having recourse to another sense, which furnishes us with the proof or intermediate idea, the knowledge obtained, even in these cases, though not amounting to intuition, is of the nature of demonstration: whence all sensible knowledge (the organs of sense being in themselves perfect, and the objects fully within their scope) falls, if I mistake not, under the one or the other of these two divisions.
DEMONSTRATIVE KNOWLEDGE, where the intervening proofs or ideas perform their part perfectly, approaches, as I have already observed, to the certainty of intuition. But it has generally been held that this kind of demonstration can only take place in the science of mathematics, or, in other words, in ideas of number, extension, and figure. I coincide, however, completely with Mr. Locke, in believing that the knowledge afforded by physics may not unfrequently be as certain. I have already stated that the knowledge we possess of our own existence is INTUITIVE. Our knowledge of the existence of a God is, on the contrary, DEMONSTRative. Examine, then, the proofs of this latter knowledge, and see whether it be less certain. Am I asked where proofs to this effect are to be found? On every side they press upon us in clusters.I cannot, indeed, follow them up at the present moment, for it would require a folio volume instead of the close of a single lecture; and I merely throw out the hint that you may pursue it at home. But this I may venture to say, that whatever cluster we take, it will develope to us a certain proof, and, in its separate value, fall but little short of the force of self-evidence. If I ascend into heaven, he is there; in peerless splendour, in ineffable majesty; diffusing, from an inexhaustible fountain, the mighty tide of light, and life, and love, from world to world, and from system to system. If I descend into the grave, he is there also; still actively and manifestly employed in the same benevolent pursuit: still, though in a different manner, promoting the calm but unceasing career of vitality and happiness; harmoniously leading on the silent circle of decomposition and reorganization: fructifying the cold and gloomy regions of the tomb; rendering death itself the mysterious source of reproduction and new existence; and thus literally making the "dry bones live," and the “dead sing praises" to his name. If I examine the world without me, or the world within me, I trace him equally to a demonstration :—[ feel,-nay, more than feel,-I know him to be eternal, omniscient, omnipotent, the creator of all things, and therefore God. I discover him, not by the vain maxims of tradition, or the visionary conceit of innate principles, but by the faculty with which he has expressly endowed me to search for him,-by my reason. There may, perhaps, be some persons, as well learned as unlearned, who have never brought together these proofs of his existence, and are therefore ignorant of him; as there certainly are others who have never brought together the proofs that the three angles of a triangle are equal to two right angles, and are therefore ignorant of geometry: but both facts have a like truth and a like foundation: both flow from and return to the same fountain: for God is the author of every truth,-for God is truth itself.
ON ANCIENT AND MODERN SKEPTICS.
From a system that is simple, intelligible, and satisfactory, adapted to the condition of man, and pregnant with useful instruction, we have now to turn our attention to a variety of hypotheses, that are scarcely in any instance worthy of the name of systems, and which it is difficult to describe otherwise than by reversing the terms we have just employed, and characterizing them as complicated, unintelligible, unsatisfactory; as not adapted to the condition of man, and barren of useful instruction.
It is a distinguishing and praiseworthy feature in the Essay on Human Understanding, that it confines itself to the subject of human understanding alone, and that, in delineating the operations of the mind, it neither enters into the question of the substance of mind, or the substance of matter; nei. ther amuses us with speculations how external objects communicate with the senses, or the senses with the mental organ. It builds altogether upon the sure foundation of the simple fact, that the senses are influenced, and that they influence the mind; and as, in the former case, it calls the cause of this influence external objects, so in the latter case it calls the effects it produces internal ideas. Of the nature of these objects it says little, but of their substantive existence; of the nature of these ideas it says little, but of their truth or exact correspondence with the objects that excite them; its general view of the subject being reducible to the two following propositions :
First, that as objects are perceivable at a distance, and bodies cannot act where they are not, it is evident that something must proceed from them to produce impulse upon the senses, and that the motion hereby excited must be Thence continued by the nerves, or connecting chain, to the brain or seat of sensation, so as to produce in our minds the particular ideas we have of them.*
And, secondly, that the ideas thus produced, so far from being images or pictures of the objects they represent, have no kind of resemblance to them, except so far as relates to their real qualities of solidity, extension, figure, motion, or rest, and number.t
Thus far, and thus far only, does the author of the Essay on Human Understanding indulge in a digression into physical science; and even for this he feels it necessary to offer an apology to his reader: “I hope," says he, “I shall be pardoned this little excursion into natural philosophy, it being neces. sary in our present inquiry." I
For myself, I am glad he did not proceed farther, and should have been still more satisfied if he had not proceeded even so far; for the subject proves itself, even in his hands, to be inexplicable; and if he be here found to evince some degree of obscurity, it is only, perhaps, because it is not possible to avoid it. Of the PRIMARY or real qualities of bodies, as he denominates them, we know but little ; and it is probable, that Mr. Locke has enumerated one or two under this head that do not properly belong to the list. And although it is not difficult to determine his meaning where he asserts that their ideas resemble them, as being drawn from patterns existing in the bodies themselves, the sense of the passage has been very generally mistaken, and opinions have hence been ascribed to him which are contrary to the whole tenor of his system. In consequence of being real representatives of real qualities, they resemble them in respect to REALITY. And this, I think, seems to be what Mr. Locke intended to express upon this subject; though he does not discover his usual clearness as to what he designed to convey by the term RESEMBLANCE. This view, however, will be still more obvious by comparing the seventh, ninth, and twenty-third sections of the
* Essay on Hum. Underst. book ii. ch. viii. 12.
: Ib. 92
eighth chapter of his second book, in which he asserts, that the SECONDARY qualities of bodies, as they are usually called, and which he contrasts with the PRIMARY before us, have no real existence in their respective bodies, and are nothing more than powers instead of qualities. And hence, while the ideas of the PRIMARY qualities of bodies are real representatives of real qualities, and to this extent RESEMBLE them, the ideas of their SECONDARY qualities are only real representatives of ostensible or imaginary qualities, in regard, at least, to the subjects to which they appear to belong, and, consequently, have NO RESEMBLANCE to them whatever.
What, however, Locke thus modestly glanced at, others, with all the confidence of the Greek philosophers, have boldly plunged into; and the consequence has been, that they have met with the very same success as the Greek philosophers, and revived the very same errors:-some having been bewildered into a disbelief of the soul, others into a disbelief of the body, and others again, still more whimsically, into a disbelief of both soul and body at the same time; contending not only that there is no such thing as a world about them, but no such thing as themselves, except at the very moment they start either this or any other idea of equal brilliance.
We have already seen, that the ideas of the mind have no resemblance whatever to the external objects by which they are produced; unless in the case of the primary qualities of bodies, in which, as just observed, the term resemblance may be applied in a figurative sense, the only sense, as I shall show more fully hereafter, in which it was ever employed by Mr. Locke.
This is a fact so clear as to be admitted by almost every school of philosophy. "Between an external object and an idea or thought of the mind," observes Dr. Beattie, "there is not, there cannot possibly be, any resemblance.” 99* So, in continuation, "a grain of sand and the globe of the earth; a burning coal and a lump of ice; a drop of ink and a sheet of white paper, resemble each other in being extended, solid, figured, coloured, and divisible; but a thought or idea has no extension, solidity, figure, colour, or divisibility: so that no two external objects can be so unlike, as an external object, and (what philosophers call) the idea of it." To the same effect Dr. Potterfield: "How body acts upon mind, or mind upon body, I know not; but this I am very certain of, that nothing can act or be acted upon where it is not; and therefore our mind can never perceive any thing but its own modifications, and the various states of the sensorium to which it is present. So that it is not the external sun and moon which are in the heavens that our mind perceives, but only their image or representation impressed on the sensorium. How the soul of a seeing man sees those images, or how it receives those ideas from such agitations in the sensorium, I know not. But I am sure it can never perceive the external bodies themselves, to which it is not present."
Now allowing this fact, it follows, of inevitable necessity, that the mind does not of itself perceive an external world, even any thing resembling an external world; and we must take both its existence and the nature of its existence upon the evidence of our external senses. Such an authority may perhaps seem tolerably sufficient to most of my audience; and I trust I shall be able to prove, before we conclude, that the external senses are as honest and as competent witnesses as any court of judicature can reasonably desire. But it has somehow or other happened, as we have already seen, that there have been a few wise and grave men, and of great learning, talents, and moral excellence, in different periods of the world, who have had a strange suspicion of their competency: and have hunted up facts and arguments to prove that their evidence is not worth a straw; that, in some cases, they have shown themselves egregious fools, and in others arrant cheats; that the testimony of one sense often opposes the testimony of another sense; that what appears smooth to the eye appears rough to the touch; that we cannot always distinguish a green from a blue colour; and that we sometimes feel great awe and solemnity beneath a deep and growing sound, which we at first take to
On Truth, part 1. ch. ii. p. 165.
be a clap of thunder, but afterward find to be nothing more than the rumbling of a filthy cart; that we mistake a phantasm, or phantasmagoria, for a figure of flesh and blood; and occasionally see things just as clearly in our dreams as when we are awake, though all the world with which we have then any concern is a world of mere ideas—a world of our own making, and altogether independent of the senses; and, consequently, that it is possible the poet may speak somewhat more literally than he intended, when he tells us
We are such stuff
This sort of reasoning, however, has not been confined to modern times; it was, as I have already observed, the very argument of Arcesilas, and the skeptics of the Middle ACADEMY, as it was called; who, in consequence, contended that there is no truth or solidity in any thing: no such thing as certainty, or real knowledge; and that all genuine philosophy or wisdom consists in doubting. From a cause somewhat similar, Pyrrho, as I have likewise remarked, seems to have carried his skepticism to a still farther extravagance, though a very excellent man and enlightened philosopher in other respects: for he is said to have so far disbelieved the real existence of every thing before him that precipices were nothing; the points of swords and arrows were nothing; the wheel of a carriage ihat threatened to go over his own neck was nothing. Insomuch that his friends, who were not quite so far gone in philosophy, thought it right to protect him against the effects of his own principles, and either accompanied him themselves or set a keeper over him under the milder name of a disciple. It was in vain that Plato pretended that the mind is loaded with intellectual archetypes, or the incorporeal ideas, of all external objects; Aristotle that it perceives by immaterial phantasms; and Epicurus by real species or effigies thrown forth from the objects themselves: Pyrrho denied the whole of this jargon, and contended that if it could even be proved that the senses uniformly give a true account of things, as far as their respective faculties extend, still we obtain no more real knowledge of matter, of the substance that is said to constitute the external world, than we do of the perceptions that constitute our dreams. If, said he, you affirun that matter consists of particles that are infinitely divisible, you ascribe the attribute of infinity to every particle; and hence make a finite grain of sand consist of millions of infinite atoms; and such is the train of argument of the atomic philosophers. While, on the contrary, if you contend, with the atomists, that matter has its ultimate atoms or primordial particles, beyond which it is not possible to divide and subdivide it, show me some of these particles, and let those senses you appeal to become the judges.
Such was the state of things under the Greek philosophers: the existence of an external world and its connexion with the mind was supported, and supported alone, by fine-spun hypotheses, that were perpetually proving their own fallacy; and was denied or doubted of by skeptics who were perpetually proving the absurdity of their own doubts.
Des Cartes, as we have already observed, thought, in his day, it was high time to remove all doubt whatsoever, and to come to a proof upon every thing; and he zealously set to work to this effect. In the ardour of his own mind he had the fullest conviction of a triumph; and like a liberal antagonist he conceded to his adversaries all they could desire. He allowed a doubt upon every thing for the very purpose of removing it by direct proofs. He began, therefore, as we have already seen, by doubling of his own existence: and, as we have also seen, he made sad work of it in the proofs he attempted to offer.
Having satisfied himself, however, upon this point, he next proceeded to prove the existence of the world around him; and, candidly following up the