two numbers. The former is the fallacy of division, | as much wealth, at least, as enables them to devote a because the middle term 5, is used collectively in the portion of their time to the cultivation of the mind. major premiss, but dividedly, 3 and 2, in the minor. The fallacy of composition is the reverse. In both there are to wholes or classes. The miracle of curing the man sick of the palsy might have been the result of chance; therefore, all miracles might have been the result of chance. This is an instance of the fallacy of composition. Fallacy of Accidents. In this fallacy, the middle term is used simply in one of the premises, but conjoined with certain accidents in the other; as, What we eat grew in the fields; loaves of bread are what we eat; therefore, loaves of bread grew in the fields. In the major premiss we eat is taken simply, but in the minor it is taken with its accidents, baked, cooked, &c. A certain medicine, when taken improperly, hurts; therefore, it is a bad medicine. It is bad when taken with its accidents, that is, improperly. Reasoning in a Circle. Argumentum ad Пominem. This signifies the argument directed point blank to the person spoken to, or a reference to something in the person's own condition which proves the truth of the argument. There is a fine instance of the legitimate use of the argumentum ad hominem in Luke's Gospel, chap. xiv. v. 5. The Pharisees, affecting to be scandalised by Christ doing works of mercy on the Sabbath, he addressed them as follows:-" Which of you shall have an ass or an ox fallen into a pit, and will not straightway pull him out on the Sabbath day?" This direct appeal was unanswerable. The argumentum ad hominem is always used fairly when the conclusion established is not considered general but particular; that is to say, when it applies to the conduct or principles of the person reasoned with, not with the principles of all mankind. No man is entitled to have his argument overturned by the doings of others. Fallacies of the Feelings. This occurs when a person pretends to determine the truth of a proposition by instancing the conclusion. The English language, by being composed of words from the Saxon and Latin languages, admits of this The feelings may be said to be always lying in wait fallacy to a great extent. A person says, A thing is to set aside the efforts of judgment. The class of falhateful. Why is it hateful? Because it is odious. lacies of this nature are intimately connected with Now, hateful and odious mean the same thing; odious interest, caprice, self-esteem, envy, jealousy, disputabeing a Latin synonyme for the Saxon word hate- tion, complaisance, outward appearance, long-sounding ful. Reasoning in this way is just as bad as saying words, inferring the motive from the effect, authority, a thing is hateful because it is hateful, or it is true manner, awe of rank, fear, &c. Bacon terms the because it is true. Why did you go to such a place? fallacies or prejudices which militate against the dissays one man to another; Because I went, is the reply.covery of truth idols, because men are apt to pay This is no answer at all. Whately gives an instance of this fallacy in the following sentiment. "To allow every man an unbounded freedom of speech must always be, on the whole, advantageous to the state; for it is highly conducive to the interests of the community, that each individual should enjoy liberty, perfectly unlimited, of expressing his sentiments." This kind of rant often passes for sound reasoning. Petitio Principii. When any one reasons on the supposition of a fact which is neither proved nor granted, he is said to beg the question, or, in the language of Logic, to resort to the petitio principii. A proposition cannot be proved to be true from something which is equally uncertain and disputed. Self-Contradiction. Some persons advance arguments which bear their own contradiction, and therefore come to nothing. A partisan will be heard to say, "The removal of the laws which prevent the free importation of foreign corn would injure the home agriculturists; but it is well known, from the most ample investigation, that foreign countries possess so little overplus of corn, or the means of sending it, that any expectation of supplies from abroad is little better than a delusion." Here the second proposition, in effect, contradicts the first. This fallacious kind of reasoning is only surpassed by the following legal jeu d'esprit :-" There are three points in this case," says the defendant's counsel. "In the first place, we contend that the kettle was cracked when we borrowed it; secondly, that it was whole when we returned it; and, thirdly, that we never had it at all." Ignoratio Elenchi. Ignoratio elenchi, or irrevelant conclusion, is when various kinds of propositions are substituted, according to the occasion, for the one that ought to be proved. The fine arts please the imagination, and adorn and polish life. But the fine arts are the parents of luxury. This does not prove the original conclusion, namely, that the fine arts are a frivolous amusement; besides, it mistakes the effect for the cause. The fine arts are the offspring of wealth, not the parent of luxury, for they can be encouraged only by a people who possess homage to them instead of regarding truth. He classes them as follows: The 1st class are called Idols of the Tribe, because they are common to the whole race or tribe of mankind; the 2d are termed Idols of the Den, because every man has his own particular den or character; the 3d class, Idols of the Market, because they are accommodated to common notions; and the 4th, Idols of the Theatre, because many systems of philosophy are but stage-plays, which exhibit nothing but theatrical worlds or visionary hypotheses. The first class are those prejudices which men entertain from their early notions, and from a love of hypothesis. Thus, an old woman who may have recommended some nostrum, which has been successful in curing one disease, will consider it a remedy for all other diseases. The second are those prejudices which arise from habits of thinking, the dispositions, or the passions of men. A theologian who is of a violent temper, will represent the Deity as implacable. The pedantic mathematician, who reasons on a subject, will not be convinced by probable conclusive reasoning, because it is not demonstrative. The third are those which arise from the relations of human society, from the condition of men, from their different stations. The man of wit laughs at the philosopher of whose speculations he is ignorant. The fourth are those prejudices which men entertain upon the authority of others. The zealous abettor of some favourite theory will never listen to any arguments against it. The following are illustrations of these various fallacies, drawn from different circumstances. Of Caprice. There are persons who will not admit that those individuals whom they happen to dislike are in any respect worthy of esteem. They seem to reason thus:-I like that man; therefore, he is the best person in the world. I dislike that one; therefore, he is a worthless fellow. Of Self-Love and Self-Conceit.-Some individuals regard all men as irrational who differ from them in opinion; all who do not agree with them are opinionative. I am a man of common sense; therefore, it is so. I have a right to be displeased with you for not succumbing. Of Envy and Jealousy.-Some men contradict with | right, for I have studied the subject, and I am a man of a mean malignity those of whom they are jealous. Their common sense. Persons of this turn of mind are envy of a person begets hatred of his opinions. I did always hurt at any one thinking differently from them, not say that; therefore, it is false. I did not write that and look upon it as a kind of personal insult, for it article; therefore, it is contemptible. amounts to calling in question their judgment. Confusion of Ideas. Of Disputation.-Disputation, or maintaining an assertion for the sake of contradiction, renders conviction difficult, if not impossible. When some disputants find that a position is not to be defended, they trust to equivocation; some affect contempt or modesty, so reproach themselves in order to get rid of an adversary; others defend themselves with the only weapons they can use to advantage-the strength of their voice and lungs. Of Interest.-A difference of judgment not unfrequently proceeds from interested motives. I am a native of this country; therefore, I must believe that every interesting event recorded in its early history actually occurred. My interest is apparently damaged" Well," said the man, "I have not taken it." "But by a certain public measure; therefore, I must oppose it. I have nothing to do with the effect which it may have on the country generally. Of Complaisance. Some persons either commend what is reprehensible, or more than is just, and therefore delude those that are so commended, and wrong those that really merit praise. Of Outward Appearance. There are some individuals who overrate the value of whatever at once captivates the senses; and who undervalue whatever requires obseration and thought to be duly appreciated. The colours of the painting are beautiful; therefore, the design is admirable. That is a fine-looking man. What a fine orator! What a good man he is! Of Sounding Words.-There are individuals who never discover the false statements and the invalid reasoning which are found in some tastelessly decorated productions. The figures set them a-gazing; the periods tickle their ear; and the sound of the words allures them to thoughts so frivolous that a child would reject them, if expressed in suitable language. Of Inferring the Motive from the Effect.-There are not a few men who regard every change of opinion as a sign of fickleness; who distinguish neither fortunate from prudent, nor unfortunate from vicious. He has changed his opinions in regard to popular education; therefore, he is a mere weathercock. He did not pay that respect to Mr A. which was expected; therefore, he is proud and vain. He is of the same opinion in regard to geology as Mr C.; therefore, he is doubtless as heretical in his opinions. Nay, he is unquestionably an atheist, and something worse. Of Authority and Manner.-Some men test the truth of an assertion by authority which they have been led accidentally to revere. There are others, again, who are disposed to test it by the manner in which it is propounded. Their reasoning, tacitly and involuntarily, is This is the opinion of Mr A., the leader of my party; it is therefore correct; I have no need whatever to examine it. T. is a man of no fortune what is his opinion worth? The speaker had a fine showy manner; it was quite impossible to hear him without reasoning correctly, and feeling rightly. How completely he demolished his opponents! Iis very manner showed that he despised them all. It was quite sufficient that he proved a part only of what he was to prove, for he left his audience to infer the rest. It may be true that he imputed to his opponents certain sentiments which they utterly repudiate; but his authority and manner made good the imputation. That many such sophisms as the above are frequently to be met with, must occur to every sound observer who mixes with the world. Dogmatising. This is but a branch of the above. When a person utters his own opinions, and endeavours to force them on his hearers, right or wrong, he is said to dogmatise, that is, lay down his dogmas or opinions in an improper manner. Few things are more common than this fallacious mode of disputation, which clearly inates in excessive self-esteem. What I say is Fallacies in reasoning often lurk under a confusion of ideas, and to produce this confusion is often the object of cunning and dishonest arguers. A tricky man went into the shop of a rather simple-minded woman, and asked for a penny loaf and a penny glass of gin. The articles being given, he drank the gin, and addressed the woman as follows:-" On second thoughts, I will not take the bread; therefore, I just give it back in payment for the gin." The woman, somewhat perplexed, answered, “" But you did not pay me for the bread." where is the payment for the gin?” "My good woman," replied the man, "haven't I told you already that I have given back the penny loaf for it." This piece of sophistry so confused the ideas of the poor woman, that she allowed the villain to depart. Very simple questions may in this manner be made to assume an air of extraordinary difficulty. A herring and a half for three halfpence, how many for elevenpence? is a jocular question, which has perplexed many at first sight. Suppressio Veri. Suppressio veri, or the suppression of the truth, is a common and dishonest method of reasoning on a question. The thing is done in various ways. A person under examination by a committee of the House of Commons respecting education, is asked if he thinks it right to give "special religious instruction in schools!" He answers that "he would not give special but genethis answer in print, and in order to injure the repural religious education in schools." An opponent sees tation of the respondent, he says that Mr So-and-So "declared that he would not give religious education in schools." Here the truth is suppressed; the word special has been left out. This is called garbling a sentence to suit a bad purpose. The following is an analogous mode of procedure. A statistical writer, after making an elaborate inves tigation, publishes a statement of facts and figures to show that a particular corporation is in a state of insolvency. His inferences, which are quite fair, are met, not by an analysis and disproval of his statement, but by an exposure of an error in his calculations, to the extent of three shillings and sixpence! This trifling error is thereupon made to form the foundation of a train of reasoning tending to show that the writer of the statement is ignorant of arithmetic, that he is rash This species of dishonest reasoning is common among in judgment, and altogether wrong in his calculations. the warm adherents of party. A person is openly ac cused in an assembly of being concerned in appropriating the public money. Another rises to refute the calumny; says the accused is a most estimable individual-he is a good father and an exemplary husband; but not one word as to the actual merits of the question; and by this clap-trap appeal to feelings and the force of language, all inquiry on the subject is pre vented. Professional spite, also, sometimes takes this form of equivocation. Instead of meeting the truth of any statement respecting the qualification of a rival, some point is dragged forward in reply, with which the argument has nothing to do. "That man is an excellent lawyer," says A. B does not meet this with a denial or approval, but answers-"Did you hear he was once a bankrupt?" or, "that he was brought up on charity (" or makes some other observation equally aside from the question. Logical Analysis. In analysing a train of reasoning-1. Begin with the concluding assertion; 2. Trace the reasoning back wards, and observe how that assertion is proved; 3. The assertion will be a conclusion, and the proof of it a premiss; 4. Ascertain whether the reasoning thus obtained is conclusive; 5. Pursue with each premiss the same plan, until you arrive at the premises with which the whole commences. Any train of reasoning, therefore, should contain leading or major premises, and subordinate or minor premises. In some instances, it may be found that every step backwards in the reasoning is correct, till we arrive at the final or major premises, which rest on no solid foundation. Unfair arguers are apt to set a plain person off his guard by making him grant certain premises. The Socratic method of arguing was of this nature. The opponent was asked question after question, or, in other words, to give up point after point, till he was lost in a labyrinth, and then he was at the merey of his enemy. In Smith's Wealth of Nations, in the chapter on the Division of Labour, we are afforded an example of fair analysis. The concluding assertion is-The division of labour increases wealth. The proofs advanced in support of the assertion are-1st, Because it increases the dexterity of the workman; 2d, It saves time; 3d, It gives rise to invention. And then those proofs are proved Because the man who confines his attention chiefly to one department of labour works with more dexterity than one who prosecutes different sorts of labour. He who is constantly engaged at one kind of labour, does not lose time in passing from one sort of work to another. Useful inventions have generally been made by those individuals who had occasion to give their attention chiefly to their own sort of employment. The major premiss of the conclusions respectively are-Whatever increases dexterity increases wealth. Whatever saves time increases wealth. Whatever gives rise to invention increases wealth. Ultimate Conclusion. The Division of Labour increases Wealth. Proved by-Major Premiss. Whatever promotes dexterity increases wealth. Minor Premiss. The division of labour promotes dexterity. The division of labour gives rise to invention. The division of labour is the division of it into a number of branches or departments. Labour means, 1st, Employment; 2d, The act of labouring; 3d, The result of labour. Wealth is that which is necessary, useful, ar agreeable to man, and also exchangeable. Analogy. Analogy is a consistent reference of one thing to another; and a want of this consistency leads to serious errors in reasoning; thus, it may be said-Birds swallow small stones to aid digestion, therefore men should do too. No Christian minister ought to marry, because St Paul recommends celibacy. Wealth demoralises a nation, because it demoralises some individuals. Here the proofs are inconsistent or untrue. There is not such a degree of resemblance between the stomach of a bird and that of a man, as warrants us to affirm of the one what was affirmed of the other. St Paul dissuaded the Christian ministers of his time from marrying, because their families would have been persecuted; but the families of clergymen in our time have no such thing to fear. Wealth has not the same effect on a nation that it has on an individual. It may render some individuals proud, indolent, and prone to luxury; but a wealthy nation is industrious, and by no means comparatively proud, DOCTRINE OF SYLLOGISMS.-SOPHISTRY. From the preceding definition of propositions and predicables, it will appear that from truth nothing can really follow but what is true; whensoever, therefore, we find a false conclusion drawn from premises which seem to be true, there must be some fault in the deduction or inference, or else one of the premises is not true in the sense in which it is used in the argument. When an argument carries the face of truth with it, and yet leads us into a mistake, it is a sophism. It being of importance that every thing like sophistry, or a semblance of truth without the reality, should be avoided in processes of reasoning, we shall, at the risk of a little recapitulation, explain the fundamental grounds of reasoning, according to the doctrine of syllogisms. When unable to judge of the truth or falsehood of a proposition in an immediate manner, by the mere contemplation of its subject and predicate, we are constrained to use a medium, and to compare each of them with some third idea. The three parts so formed are a syllogism. For example, we take the following, given by Watts: Our Creator must be worshipped; Therefore, God must be worshipped. Here it may be observed that the third term or conclusion rests on a foundation afforded by the two preceding. To ensure truth in the conclusion, the premises, major and minor, must be true, and strictly agree. We have another example, as follows:Every wicked man is truly miserable; All tyrants are wicked men ; Therefore, all tyrants are truly miserable. In forming syllogisms, great care requires to be taken to construct them in such a manner that the first and second terms are analogous, and not a mere play of words. Previous to the method of reasoning from an induction from established facts, introduced by Bacon, it was usual to reason sophistically from premises presumedly true, and consequently the most false conclusions were arrived at. The logic in vogue was that of the ancient Greek philosopher Aristotle, which it was a species of heresy to deny." Men were every where taught to believe in matter, form, and privation, as the origin of all things; that the heavens were self-existent, incorruptible, and unchangeable; and that all the stars were whirled round the earth in solid orbs! Aristotle's works were the great text-book of knowledge, and his logic was the only weapon of truth. Men's minds, instead of simply studying nature, were in an endless ferment about occult qualities and imaginary essences; little was talked of but intention and remission, proportion and degree, infinity, formality, quiddity, individuality, and innumerable other abstract notions. The Latin tongue, which was employed by these scholastics, was converted into a barbarous jargon, which a Roman would not have understood; and in the end, the most sectarian bitterness was produced, sometimes ending in bloody contests. In the midst of these disputes, Aristotle was still the grand authority. Christians, Jews, and Mahometans, united in professing assent to the great lawgiver of human opinions: not Europe alone, but also Africa and Asia, acknowledged his dominion; and while his Greek originals were studied at Paris, translations were read in Persia and Samarcand. The rage for disputation which now began to prevail in consequence of the spread of this philosophy, induced the council of Lateran, under Pope Innocent III., to proclaim a prohibition of the use of the physics and metaphysics of Aristotle; but, awful as were then the thunders of the Vatican, they were not mighty enough to dethrone him from that despotism over men's minds which, by long custom, had now rendered itself almost omnipotent." It was reserved for Lord Bacon to break the mighty power of Aristotle's philosophy, and to sub Account of Lord Bacon's Novum Organon, in Library of Useful Knowledge. stitute that which is now in use.* The errors of the sophists, which it may be advantageous to examine, were of two leading orders. The fault, in the first instance, may reside in the expressed argument, or syllogism, in which the conclusion does not follow from the premises it is apparently involved in; or, secondly, it may lurk in the concealed process of thought, dexterously suggested by the sophist, by means of which false premises are regarded as proved, and a false though logically legitimate conclusion is of course necessitated; or in which a conclusion, likewise logically fair, and probably true as matter of fact, but irrelevant or only partially relevant to the point at issue, is admitted as applicable and decisive. In the one class, the link is wanting which should bind the inference to the previous positions; in the other, that is absent which should connect either with the real subject of dispute. A sophism, then, which is inseparable from the form of the expression, may perhaps with propriety be styled syllogistic; while one attaching to the subject-matter may fall to be treated as extra-syllogistic. It is obviously as respects the latter sort that the human mind is most open to deception; and it must at the same time be allowed that logic is here, where her aid is most essential, able to lend it but in scanty measure. The candid will, however, remember that even the meanest modicum of such service is of value, and will not quarrel with an art for failure where absolute success is plainly unattainable. | instance, from confounding allied meanings of the same term. Sometimes a word is used both in its primary and in a transitive sense. An instance in point occurs in Mr Burke's Essay on Taste, prefixed to his celebrated disquisition on the Sublime and Beautiful. "It may perhaps appear," he observes, "that there is no material distinction between the wit and the judgment, as they both seem to result from different operations of the same faculty of comparing. But, in reality, whether they are or are not dependent on the same power of the mind, they differ so very materially in many respects, that a perfect union of wit and judgment is one of the rarest things in the world." The words wit and judgment have each, in the above passage, two distinct significations-the powers thus denominated respectively, and the products of both in peculiarly lively exercise. The inference, of course, does not hold, and the objection it is intended to meet remains unanswered. Sometimes a metaphorical sense is slipped in, in place of the literal. We have heard that a popular orator thus managed to turn to his own account the misfortune of a rival, absent, it seems, from delicate health. "The gentleman has said he cannot venture himself in such an atmosphere, but this is the atmosphere in which I delight to breathe." With an excited crowd, this flimsy artifice, we believe, succeeded in procuring for a stout pair of lungs the applause due to distinguished patriotism. Occasionally, the extension of a term is changed. Thus Hume, in his Essay on Miracles, argues as if what is granted of ordinary were true of universal erperience. Because events of this order have not come under the observation of most persons, it is concluded that they could never have come under the observation of any. A like ambiguity has sometimes arisen from the vague application of authority. Referring to the writer last named, in his capacity of historian, we may think fit to pronounce him an excellent autho First, then, of syllogistic fallacies; which, indeed, by excessive generalisation, might be comprised under the other class, since they are resolvable into the impression that the same or similar terms are always representative of the same or similar ideas. It is much more convenient, however, to consider them separately. Errors of this description may proceed, in the first * Francis Bacon, created Baron Verulam, who rose to the rank of Lord Chancellor of England in the reign of James I., obtained the highest reputation as a philosophical writer. In 1620, ap-rity; but unless the term be expressly guarded, we peared his chief production, in a complete form, "The Novum Organon, or New Method of Studying the Sciences," in which he pointed out the way in which we should begin and carry on our pursuit of knowledge in order to arrive at truth. The principles he laid down were to ascertain facts in the first place, and then to reason upon them towards conclusions—a mode which may now appear very obvious, and even unavoidable, but which was nevertheless unknown till explained by him. To come to particulars, Bacon tells us I. That the ultimate aim of philosophical investigation is to bring the course of events as much as possible under our own control, in order that we may turn it to our own advantage. II. That as each event depends upon a certain combination of circumstances which precede it, and constitute its cause, it is evident we shall be able to command the event whenever we have it in our power to produce that combination of circumstances out of the means which nature has placed within our reach. III. That the means of producing many events which we little dream of, are actually placed within our reach; and that nothing prevents us from using those means, but our inability to select them from the crowd of other circumstances by which they are disguised and surrounded. IV. That therefore we should endeavour, by diligent observation, to find out what circumstances are essential, and what extraneous, to the production of each event; and its real cause being stripped free from all the perplexing concomitants which occur in nature, we shall perceive at once whether we can command the circumstances that compose it or not. This, in short, is to generalise; and having done so, we shall sometimes discover that objects, which of all others appeared the most useless, remote, and inapplicable to our purpose, possess the very properties we are in search of. Nature stands ready to minister to our designs, if we have only the sagacity to disentangle its operations from one another, to refer each event to its real source, and to trace the powers and qualities of objects into their most abstract form. In pursuing the dictates of this noble philosophy, man is no longer impotent and ridiculous. He calmly vanquishes the barriers which oppose his wishes-he eludes the causes of pain-lie widens the range of enjoyment-and, at the same time, feels the dignity of intellect, which, like a magician's talisman, has made all things bow before his feet. In may be represented as intimating our approval of his It is A second class of errors in reasoning, belonging to the same general order, may arise from the oversight of certain differences betwixt related terms. It is often, for example, taken for granted that words springing from a common root only vary among themselves as parts of speech, whereas, in fact, the radical meaning ray have become considerably modified. Schemer denotes an artful, truckling, unprincipled individual-qualities that chanced to be the author of a scheme. The two | always to be rejected; opium is a deleterious drug; terms are related to each other, but a devout man is not therefore a devotee. In some instances, however, the derivative and primitive differ too plainly for either to become available for the purposes of sophistry. A mind that would fail to detect the transition from art to artful, from pity to pitiful, and the like, must be under the influence of principles of association no less peculiar than those which led the Laird of Ellangowan, in Guy Mannering, to give justice embodiment in a justice of the peace. To this head we would also refer the disingenuous use of pseudo-synonymes-that is, terms corresponding generally, but not alike expressive of the required shade of distinction. To murder, and to put to death, both indicate agency with a similar result; but the former phrase determines that agency to be criminal, while the latter affixes no such character to it. Many, under the impression that the terms are perfectly equivalent and interchangeable, might be induced to ascribe to sour substances the recognised properties of bitter. It is unnecessary to multiply examples. Let us now review briefly the more frequent and more dangerous species of fallacies which we have ventured to denominate extra-syllogistic. The fault here was described as attaching, not to the expressed process of argument, but to the concomitant process of thought. Sophisms, ranging under this general category, are all traceable to two sources, the first of which is the mption of doubtful premises. This error appears in a great variety of forms. Accidental coincidence is often assumed as sufficient to establish efficient connexion. Two events happen nearly At the same time; therefore one is supposed the cause, and the other the effect. Of this sort of false reasoning, we remember a notable instance in Prideaux. Cambyses was mortally wounded by his sword piercing bis body in the same part in which he had stabbed the sacred bull of the Egyptians. In narrating this madent, the dean expresses his concurrence in their uperstitious inference, observing that the mode of the king's death was probably designed to mark the divine displeasure against his act of violence, as an insult offered to the cause of religion in general. On the same error are based the fictions of astrology. The fate of individuals and of nations has been thought to be bound up in the movements and conjunctions of the stars; and so simple an event as the appearance of a comet has ere now frightened Europe into penitence. Virgil, in his first Georgic, bids the farmer confide in those indications of the weather afforded by the aspect of the sun, since that luminary's obscuration gave faithful warning of the impending doom of Cesar. On the same principle, the decline of the Roman power was early ascribed to the spread of Christianity. All our popular superstitions are to be amilarly explained; those, for instance, which interret as infallible preludes of death or discord, the chirping of an insect, the howling of a dog, or the spilling of a little salt. Closely allied to the preceding fallacy is that which Consists in the assumption of a hypothetical cause. At tas stumbling-block we find the father of logic himtripping. "All the heavenly bodies," says Aristotle, in his Physics, "must move in circles, because a rcle is the most perfect of all figures." The reason tere assigned for a position, now known to be at vari10ce with existing phenomena, is neither appreciable itself nor applicable to the question. Des Cartes's pothesis of animal spirits, and Hartley's theory of vibrations, both framed to explain the transmission of enable impressions from the extremity of the nerves to the brain, are both referable to the same source of error-the supposition, namely, that when a possible cause has been assigned, the real cause has been dis covered. What is true with limitations, is frequently assumed to be true absolutely. Thus "Deleterious drugs are therefore, opium is always to be rejected." It is plain, that a maxim which holds good, generally, of persons in health, is not applicable, specially, to cases of disease. This sophism appears, perhaps, more frequently in the interrogative than in the categorical form. The object of the disingenuous disputant, then, is to extort from his adversary an unconditional answer to a question so put as to require it to be qualified. When the query is advanced in a bold, triumphant tone, with its real complexity dexterously disguised, a timid and inexperienced debater will be easily silenced by this expedient. The question, for example, "Is war detestable, or is it not?" cannot be answered directly and unconditionally. If we choose the affirmative, we concede the criminality of even defensive war; if we prefer the negative, we are dealt with as the advocates of aggressive. We must explain and qualify, if we would avoid either horn of the dilemma, at the risk, indeed, of being accused by our opponent of a wish to shuffle and prevaricate, and perplex the discussion. To this head, most cases of defective parallel may conveniently be referred. Again: We may assume, as exhaustive of all the alternatives of a given case, what embraces only a portion of them. Thus, in one of Lucian's Dialogues of the Dead, Menippus chooses to take for granted that the misery of Tantalus only arises from fear that he may die of thirst; and proceeds, accordingly, in sarcastic vein, to prove the apprehension groundless." You say you are punished with thirst; but why is that dreadful to you? For I see no region besides this Hades, nor any second death in another quarter." Thus, too, the celebrated sophistical puzzle respecting motion. "Whatever body is in motion must move either in the place where it is, or in some place where it is not; neither of these alternatives is possible; therefore, there is no such thing as motion." Here it is assumed, that there is no such third alternative as is conveyed by the prepositions from and to, the others involving manifestly à contradiction in terms. Next may be mentioned the error of assuming that what is true of a whole is true of a part. Crities, on this principle, have conceived themselves bound to vindicate, or puff into beauties, even the most flagrant faults of standard writers; and have seldom struck the medium between unqualified censure and extravagant praise. How often are meritorious individuals subjected to the odium, attaching, perhaps justly, to the majority of a class to which they chance to belong! How often are salutary institutions and customs neglected or decried, just because they have a common origin with others that are noxious and blameworthy! To reverse the illustration: How often are particular periods characterised as enlightened and prosperous, simply from a partial survey of the aspect of affairs! Take the era of Elizabeth. "There was, perhaps, a learned and vigorous monarch, and there were Cecils and Walsinghams, and Shakspeares and Spensers, and Sidneys and Raleighs, with many other powerful thinkers and actors, to render it the proudest age of our national glory. And we thoughtlessly admit on our imagination this splendid exhibition as in some measure involving or implying the collective state of the people in that age.' And how much pernicious error has, in like manner, resulted from admitting the impression that every wise man has been always wise, every great man always great, and every good man always good. It may be assumed that a position must be false because of certain consequences supposed to follow from it. These consequences may not follow. The truth of Galileo's astronomical theory did not infer the falsehood of the Scriptures, but merely the falsehood of the received interpretation of them. Or they may follow, and the position still be tenable. To have alleged that Galileo's theory was inconsistent with the Ptolemaic system of the universe, would have been true, but nugatory. Foster's Essay on Popular Ignorance. |