we hope to be able to save students from the fate of diodorus, (a great logician, who died in his school through shame at being, unable to resolve a quibble propounded by stilno)—not by hardening, but by enlightening them. though we bring neither mood nor figure wherewith to test the presence of error, we are not without the hope of qualifying the student for its discovery.
it has been confessed from the throne of logic that, 'after all, in the practical detection of each individual fallacy, much must depend on natural and acquired acuteness: nor can any rules be given, the mere learning of which will enable us to apply them with mechanical certainty and readiness.'
bulwer, in remarking that error is a view of some facts instead of a survey of all, indicated the key to logical fallacy. error lies principally in defective premises. sophistry in science is referable to incomplete analysis of nature, of systems—to artificial arrangements—to supposing qualities, to assuming principles, to false inductions from imperfect demonstration.
dickens, in 'nicholas nickleby,' gives the case of a certain lady, who, because she knew one young milliner, who retained red cheeks and did not die of consumption, was immovably of opinion that all representations of the injurious effect of such sedentary occupation were false. it is ever so with the vulgar. some one case has come under their notice, and it is in vain that you appeal to a chain of facts. they know nothing of induction—they know one case to the contrary, and that is enough. this error is the source of vulgar prejudice. once teach men that truth does not lie in a single instance, but in a calculation in a balance of probabilities, and you rationalise them. 'the chapter of accidents [or single instances] is the bible of the fool—it supplies him with a text against everything great, or good, or wise.'*
* times.
where others toil with philosophic force,
their nimble nonsense takes a shorter course,
flings at your head convictions in the lump,
and gains' remote conclusions with a jump.—cowper,
the first source of error is defective induction. we easily arrive at this point of examination by the questions we have proposed for use in the test of syllogism. formerly, one syllogism was required to be defeated by another—we now attack a fallacy by induction. no false syllogism, says biennan, can resist the inductive process of sifting particulars.
i do not like thee. dr. fell,
the reason why, i cannot tell—
but this i know, and know full well,
i do not like thee, dr. fell.
this kind of thing will not do. induction pursues the reasoner with an eternal why. a clear because to a clear why, is a demand that is never remitted in sound logic.
lord melbourne, in giving his reason for his religion in the house of lords, said it was the religion of his forefathers and that of his country, therefore, he would support the church. (cheers from the opposition benches.) the brahmin and mussulman give the same reason for theirs. a logician in facts would have said, i hold and support my religion because it is true. what the standard of physical certainty is to facts, what axioms are to science, such is induction to syllogisms—it is the test of their correctness.
dr. whately exhibits the following instance of a regularly expressed syllogism:—
every dispensation of providence is beneficial:
afflictions are dispensations of providence,
therefore, they are beneficial.
every applicable rule of dr. whately's logic is, of course, applied here—it is true in mood and figure, and yet the argument is fallacious. a fallacy is defined as 'an ingenious mixture of truth and falsehood, so entangled as to be intimately blended—that the falsehood is, in chemical phrase, held in solution: one drop of sound logic is that test which immediately disunites them, makes the foreign substance visible, and precipitates it to the bottom.'* but whence is to come 'this drop of sound logic?' not from the doctor's elements, they have sent forth the fallacy. but touch it with the talisman of facts and; the error will appear.
* whately's logic, anal. out., chap. 1, stc. 4.
what facts support the assertion that afflictions are dispensations of providence?' the simple question is fatal to the argument. can such a proposition have facts for its support? ignorance, congregating in narrow courts, and laziness, accumulating filth, generate sickness and affliction. are these the dispensations of providence, or the dispensations of folly and crime? to ascribe them to providence is virtually to allow ignorance and laziness to step into the throne of god, and call upon men to believe in their beneficent dispensations. dr. watts, another writer on logic, set the christian congregations of england to sing the same species of fallacy:—-
"diseases are the servants, lord,
they come at thy command;
i'll not attempt a murm'ring word,
against thy chast'ning hand."
according to this lyrical logician, whenever wise precautions arrest the progress of pestilence, or the physician's skill subdues disease, jehovah is robbed of a servant. by such an argument, humanity is made to be in rebellion against heaven, and our medical colleges are in antagonism with deity, and the recent appointment, by the russell government, of a sanatory commission, was high blasphemy. it is the degradation of language to employ it to such a purpose, and logic needs revising to save us from publishing such puerility in the name of learning and of reason. it must have been logic of this kind that induced a strong-thoughted woman to hazard the bold but tenable conjecture, that 'if an argument has truth in it, less than a philosopher will see it—and if it has not, less than a logician will refute it.'*
* a few days in athens, by frances wright.
r. g. latham, m.d., in his 'first outlines of logic applied to grammar and etymology,' has introduced the particular instance of the syllogism on providence here cited from whately. it would be no difficult task to present other instances of the same species of polemical fallacy from dr. whately and other writers on logic, did it comport with the rule i have chosen for observance. i give these cases chiefly to show how extensively and obtrusively they are introduced.
'we have,' says mr. mill, 'five distinguishable classes of fallacy, which may to expressed in the following synoptic table:—
mill's fallacy table
it was the boast of archimedes, that if any one would find him a fulcrum, on which to rest a prop, he would raise the world, but this was mere assertion unsupported by facts, for if the fulcrum had been found him, archimedes could not have performed his promise. this has been proved by ferguson, who has demonstrated that if archimedes could have moved with the swiftness of a cannon ball—480 miles every hour—it would have taken him just 44,963,540,000,000 of years to have-raised the world one inch. bulwer remarks, 'critics have said, what a fine idea of archimedes! but how much finer is the fact that refutes it. one of the sublimest things in the world is plain truth.'
all motion generates warmth,
shaking (with cold) is motion,
ergo, shaking with cold generates warmth.
we look, in this case, to the facts on which the first proposition rests, and find the assertion too general.
to one who said that none were happy who were not above opinion, a spartan replied, 'then none are happy but knaves and robbers.'
mr. goodrich, the original peter farley gives, in his 'fireside education,' an instance to this effect of two boys arguing on the division of their beds. william exclaims, 'you take more than your share of the bed, james.' james answers, 'i only take half the bed.' william replies, 'true, but you take your half out of the middle, and i am obliged to lie on both sides to get my half.'
innumerable sophisms are suffered to pass in consequence of some brilliancy of position which, dazzles us and prevents our seeing that they are wide of the' mark of reason. an instance occurs in bulwer—who says, 'helvetius erred upon education—but his dogma has been beneficial.' probably so—but not so beneficial as the truth would have been. many persons have argued from such an instance, that error is useful. dickens, in those incidental observations of striking good sense strewed up and down his writings, says, in the 'cricket on the hearth:'—'these remarks (of mrs. fielding) were quite unanswerable: which is the happy property of all remarks that are sufficiently wide of the purpose.' of the refutation of such remarks he has presented an able instance in 'martin chuzzlewit':
'bless my soul, westlock,' says pinch, is it nothing to see pecksniff moved to that extent and know one's self to be the cause? and did you not hear him say that he could have shed his blood for me?
'do you want any blood shed for you?' returned westlock with considerable irritation. 'does he shed anything for you that you do want? does he shed employment for you, instruction for you pocket money for you? does he even shed legs of mutton for you in any decent proportion to potatoes and garden stuff?'