Authors/Ockham/Summa Logicae/Book III-4/Chapter 18
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CAP. 18. QUOMODO OMNES FALLACIAE PECCANT CONTRA SYLLOGISMUM. | Chapter 18. How all these fallacies err against the syllogism |
Post praedicta restat videre quomodo praedictae fallaciae peccant contra syllogismum et quomodo paralogismi, qui videntur syllogismi completi et non sunt, deficiunt a natura syllogismi. | After the above, it remains to see how the aforementioned fallacies err against syllogism and how paralogisms, which seem to be complete syllogisms and are not, fall short of the nature of syllogism. |
Et de fallaciis iuxta quas sunt orationes multiplices non est difficile hoc videre. Tales enim paralogismi vocaliter similes sunt veris syllogismis, sicut patet de aequivocatione in talibus paralogismis `omnis canis currit; caeleste sidus est canis; igitur caeleste sidus currit', `omnis homo est animal rationale; haec statua est homo; igitur haec statua est animal rationale', `nullum animal est species; homo est species; igitur homo non est animal'. Isti enim paralogismi vocaliter eodem modo formantur quo formantur perfecti syllogismi; nec est hic aliquis defectus syllogismi nisi quia in quolibet illorum est aliqua propositio distinguenda penes aequivocationem. Iuxta amphiboliam sic formantur paralogismi `omnis propositio vera, si est necessaria, est possibilis; te esse asinum est propositio vera si est necessaria; igitur te esse asinum est possibile', `quicumque vendit oleum, est mercator; iste adulator vendit oleum; igitur iste adulator est mercator', `quidquid est alterum istorum et reliquum istorum, est utrumque istorum; aliquod verum est alterum istorum et reliquum istorum; igitur aliquod verum est utrumque istorum', demonstratis duobus contradictoriis. | And it is not difficult to see this about the fallacies according to which there are multiple arguments. For such paralogisms are verbally similar to true syllogisms, as is clear from the equivocation in such paralogisms as `every dog runs; a celestial star is a dog; therefore a celestial star runs', `every man is a rational animal; this statue is a man; therefore this statue is a rational animal', `no animal is a species; man is a species; therefore man is not an animal'. For these paralogisms are verbally formed in the same way as perfect syllogisms are formed; nor is there any defect in the syllogism here except that in each of them there is some proposition to be distinguished according to equivocation. According to amphiboly the paralogisms are thus formed `every true proposition, if it is necessary, is possible; that you are an ass is a true proposition if it is necessary; therefore that you are an ass is possible', `whoever sells oil is a merchant; that flatterer sells oil; Therefore that flatterer is a merchant', 'Whatever is one of these and the other of these, is both of these; something true is one of these and the other of these; therefore something true is both of these', having demonstrated two contradictory things. |
In istis paralogismis nullus est defectus a veris condicionibus syllogismi nisi quod in eis est aliqua oratio multiplex secundum amphiboliam. Iuxta compositionem et divisionem sic formantur paralogismi `quicumque vivit semper est; iste vivit; igitur iste semper est'. | In these paralogisms there is no defect from the true conditions of the syllogism except that in them there is some multiple expression according to amphiboly. According to composition and division the paralogisms are thus formed `whoever lives always exists; this one lives; therefore this one always exists'. |
Iuxta accentum sic formantur `nullus iustus debet pendere; iste est iustus; igitur iste non debet pendere'. | According to accent, they are formed like this: ``No just man should hang; this one is just; therefore this one should not hang. |
Iuxta fallaciam figurae dictionis sic formantur paralogismi `omnis substantia est subiecta accidenti; omne animal est substantia; igitur omne animal est subiecta accidenti', `quidquid heri emisti, hodie comedisti; tu heri emisti carnes crudas; igitur tu hodie comedisti carnes crudas'. | According to the fallacy of figure of speech, the paralogisms `every substance is subject to an accident; every animal is a substance; therefore every animal is subject to an accident', `whatever you bought yesterday, you ate today; you bought raw meat yesterday; therefore you ate raw meat today' are formed. |
In istis enim non servatur forma syllogistica, sicut patet per regulas prius datas de syllogismo et speciebus eius. Similiter hic est fallacia figurae dictionis, deficiens a condicionibus syllogismi `quodlibet aliud a Deo potest Deus facere sine alia creatura; equitare est aliud a Deo; igitur equitare hominem sine equo potest Deus facere'. | For in these the syllogistic form is not observed, as is clear from the rules given earlier about the syllogism and its species. Similarly, here is a fallacy of the figure of speech, failing the conditions of the syllogism: `anything other than God can God do without another creature; to ride is something other than God; therefore God can make a man ride without a horse'. |
Iuxta accidens sic formantur paralogismi `homo currit; Sortes est homo; igitur Sortes currit', `iste canis est tuus; iste canis est pater; igitur iste canis est pater tuus'. In istis enim paralogismis et in omnibus paralogismis accidentis servatur debita forma in praemissis, sed in primo paralogismo non servatur modus, quia praemissae non disponuntur modo convenienti, ideo non est syllogismus. | According to accident, the paralogisms `a man runs; Socrates is a man; therefore Socrates runs', `this dog is yours; this dog is a father; therefore this dog is your father' are thus formed. For in these paralogisms and in all paralogisms of accident the due form in the premises is preserved, but in the first paralogism the mode is not preserved, because the premises are not arranged in an appropriate manner, therefore it is not a syllogism. |
In secundo paralogismo, quamvis praemissae convenienter disponantur, tamen conclusio non convenienter infertur ex praemissis, quia maior extremitas et minor extremitas coniunguntur a parte eiusdem extremi et medius terminus ponitur in conclusione; quorum utrumque repugnat syllogismo, propter quod forma syllogistica non servatur ibidem. | In the second paralogism, although the premises are arranged appropriately, the conclusion is not appropriately inferred from the premises, because the major extreme and the minor extreme are joined on the part of the same extreme and the middle term is placed in the conclusion; both of which are contrary to the syllogism, because of which the syllogistic form is not preserved there. |
Et ita non sunt completi syllogismi. | And thus they are not complete syllogisms. |
Iuxta fallaciam consequentis sic formantur paralogismi `omnis homo currit; omnis homo est animal; igitur omne animal currit'. Hic enim est defectus syllogismi, quia infertur conclusio universalis quae debet esse particularis. Iuxta fallaciam secundum quid et simpliciter formantur sic paralogismi `nullus prudens vult ditare inimicum suum; iste homo est prudens; igitur iste non vellet propter bonum rei publicae ditare inimicum suum'. Hic non est aliquis defectus, nisi quia aliqua determinatio additur in conclusione quae non erat accepta in praemissis, et ideo est fallacia secundum quid et simpliciter. Iuxta ignorantiam elenchi sic formantur paralogismi: concesso quod Aethiops est niger, arguitur ad probandum quod Aethiops non est niger, sic `nullum album est nigrum; Aethiops est albus secundum dentes; igitur Aethiops non est niger'. Hic enim est fallacia, quia in contradicendo respondenti accipitur non absolute quod | According to the fallacy of the consequent, the paralogisms `every man runs; every man is an animal; therefore every animal runs' are thus formed. For this is a defect in the syllogism, because a universal conclusion is inferred which should be particular. According to the fallacy secundum quid et simpliciter, the paralogisms `no prudent man wishes to enrich his enemy; this man is prudent; therefore this man would not wish to enrich his enemy for the good of the republic' are thus formed. There is no defect here, except that some determination is added to the conclusion which was not accepted in the premises, and therefore it is a fallacy secundum quid et simpliciter. According to ignorance of the list, paralogisms are formed in this way: granted that an Ethiopian is black, it is argued to prove that an Ethiopian is not black, thus `no white man is black; an Ethiopian is white in his teeth; therefore an Ethiopian is not black'. For this is a fallacy, because in contradicting the answer, it is not accepted absolutely that |
Aethiops est albus, sed quod est albus secundum aliquam partem secundum quam non est niger, sed secundum aliam partem propter quam Aethiops est niger <non accipitur. | an Ethiopian is white, but that he is white according to some part according to which he is not black, but according to another part because of which an Ethiopian is black it is not accepted. |
Et ita non accipitur secundum idem, propter quod est ibi fallacia secundum ignorantiam elenchi. | And so it is not taken according to the same, which is why there is a fallacy there based on ignorance of the list. |
Iuxta fallacias residuas non formantur argumenta peccantia in forma, quamvis iuxta eas peccet opponens disputando contra respondentem, ideo non oportet de eis exemplificare. | According to the remaining fallacies, arguments that are faulty in form are not formed, although according to them the opponent errs by arguing against the respondent, so it is not necessary to give examples of them. |
Omne enim argumentum apparens, peccans in forma, iuxta aliquam aliarum peccat. Quarum sufficientia et numerus potest sic accipi: quia omnis paralogismus vocalis, vel secundum vocem, quantum ad pluralitatem incomplexorum et quantitatem et qualitatem propositionum assimilatur vero syllogismo, cui competunt condiciones prius positae in tractatu de syllogismo; vel non sic assimilantur syllogismo secundum vocem. Si primo modo, impossibile est quod sit ibi aliquis defectus, nisi propter alicuius orationis multiplicitatem vel incongruitatem, vel propter hoc quod idem terminus, sine multiplicitate, pro aliquo supponit in una propositione pro quo non supponit in alia. | For every apparent argument that is faulty in form, is faulty according to some other argument. The sufficiency and number of which can be understood as follows: because every verbal paralogism, either according to the word, as to the plurality of incomplexes and the quantity and quality of the propositions, is likened to a true syllogism, to which the conditions previously set forth in the treatise on syllogism apply; or they are not so likened to a syllogism according to the word. If in the first way, it is impossible that there should be any defect there, except because of the multiplicity or incongruity of some sentence, or because the same term, without multiplicity, supposits for something in one proposition for which it does not supposit in another. |
Ista propositio demonstrari non potest, sed accipitur per inductionem. Si propter primum non valeat syllogismus, quia scilicet est ibi aliqua multiplicitas: sicut isti syllogismi quantum ad numerum incomplexorum et qualitatem et quantitatem propositionum totaliter assimilantur `omnis canis currit; caeleste sidus est canis; igitur caeleste sidus currit', `omne animal est substantia; homo est animal; igitur homo est substantia'; sicut enim in secundo syllogismo maior est universalis et minor indefinita, et sicut illud idem et non aliud ponitur praedicatum in maiore et in conclusione, et subiectum minoris ponitur subiectum conclusionis, et nulla determinatio ponitur in praemissis quae non ponitur in conclusione et e converso, ita est in primo. | This proposition cannot be demonstrated, but is accepted by induction. If the syllogism is not valid because of the first, namely because there is some multiplicity there: just as these syllogisms are completely similar in terms of the number of incomplexes and the quality and quantity of the propositions, `every dog runs; a celestial star is a dog; therefore a celestial star runs', `every animal is a substance; a man is an animal; therefore a man is a substance'; for just as in the second syllogism the major is universal and the minor indefinite, and just as that same and not another is placed as the predicate in the major and in the conclusion, and the subject of the minor is placed as the subject of the conclusion, and no determination is placed in the premises which is not placed in the conclusion and vice versa, so it is in the first. |
Et tamen primus est paralogismus et non secundus, propter hoc solum quod in primo est aliqua oratio multiplex et non in secundo. Quo posito aut ista multiplicitas est ex hoc quod aliqua vox, quae non est completa oratio, multipliciter accipitur, et tunc est fallacia aequivocationis, si dictio non varietur quantum ad modum pronuntiandi. | And yet the first is a paralogism and not the second, for the sole reason that in the first there is some multiple expression and not in the second. Which being the case, either this multiplicity is from the fact that some word, which is not a complete expression, is taken in multiple ways, and then there is a fallacy of equivocation, if the expression does not vary as to the manner of pronouncing it. |
Aut est multiplicitas ex multiplicitate alicuius vocis quae potest variis modis pronuntiari et remanere dictio, vel quae potest esse dictio et oratio propter diversum modum pronuntiandi, et tunc est accentus. | Either there is a multiplicity from the multiplicity of some word which can be pronounced in various ways and remain a word, or which can be a word and a speech because of the different way of pronouncing it, and then there is an accent. |
Vel est tota oratio multiplex sine multiplicitate alicuius partis; et hoc potest esse dupliciter: vel quia illa oratio in utroque sensu uniformiter pronuntiatur, et tunc est amphibolia, vel non est uniformiter pronuntiata, et tunc est compositio et divisio. | Or the whole speech is multiple without the multiplicity of any part, and this can be in two ways: either because that speech is pronounced uniformly in both senses, and then it is amphibole, or it is not pronounced uniformly, and then there is composition and division. |
Si autem talis discursus non sit syllogismus propter solam incongruitatem, tunc est fallacia figurae dictionis; sicut hic `omnis homo est animal; omnis Sortes est homo; igitur omnis Sortes est animal'. | But if such a discourse is not a syllogism because of incongruity alone, then it is a fallacy of the figure of speech; as here `every man is an animal; every Socrates is a man; therefore every Socrates is an animal'. |
Si enim loco istius termini `Sortes' poneretur iste terminus `asinus', cui congrue potest addi signum, esset bonus syllogismus. Si autem tertio modo fiat paralogismus, adhuc ibi potest assignari fallacia figurae dictionis, quia si loco istius termini `Sortes' poneretur aliquis terminus consimilis, potens supponere pro omni eodem in qualibet propositione, nullus esset defectus. | For if in place of that term `Socrates' were put the term `donkey', to which a sign can be appropriately added, it would be a good syllogism. But if the paralogism is made in the third mode, there can still be assigned a fallacy of the figure of speech, because if in place of that term `Socrates' were put some similar term, capable of supposing for everything the same in any proposition, there would be no defect. |
Et ita propter similitudinem istius dictionis ad aliam potest quis decipi per fallaciam figurae dictionis. | And so, because of the similarity of one word to another, someone can be deceived by the fallacy of the figure of speech. |
Unde si propter hoc quod iste syllogismus est bonus `iste est animal; iste est homo; igitur animal est homo' crederet aliquis quod iste syllogismus esset bonus `iste dicit hoc; falsum est hoc, --- demonstrando istam: iste dicit falsum ---; ergo falsum dicitur ab isto', deciperetur per fallaciam figurae dictionis. Si autem paralogismus vocalis non assimilatur quantum ad numerum terminorum et qualitatem et quantitatem propositionum in omnibus vero syllogismo: vel est ibi defectus praecise propter dissimilem qualitatem vel quantitatem propositionum praemissarum, vel propter hoc quod plures te ponuntur in conclusione quam in vero syllogismo, vel est ibi defectus propter excessum terminorum incomplexorum. Si primo modo vel secundo: vel e converso est bonum argumentum vel non. Si sic, est fallacia consequentis; si non, est fallacia accidentis. Si sit ibi excessus terminorum, quia scilicet plura incomplexa ponuntur quam deberent, quia scilicet aliquid additur in praemissa quod non deberet poni; vel aliquid tale additur in conclusione: et tunc vel illud cui additur accipitur tam in praemissa quam in conclusione, tamen in una additur sibi et non in alia, et tunc est fallacia secundum quid et simpliciter; vel additur uni in praemissa quod non ponitur in conclusione, et tunc est fallacia secundum ignorantiam elenchi. | Hence, if, because this syllogism is good, `this is an animal; this is a man; therefore an animal is a man', someone were to believe that this syllogism was good `this person says this; this is false, --- demonstrating this: this person says false ---; therefore a false thing is said by this person', he would be deceived by the fallacy of the figure of speech. But if a vocal paralogism is not aligned in terms of the number of terms and the quality and quantity of propositions in all true syllogisms: either there is a defect there precisely because of the dissimilar quality or quantity of the propositions of the premises, or because more of them are put in the conclusion than in a true syllogism, or there is a defect there because of an excess of simple terms. If in the first mode or in the second: or conversely, it is a good argument or not. If so, it is a fallacy of the consequent; if not, it is a fallacy of accident. If there is an excess of terms there, namely because more simple terms are put than should be posited, namely because something is added to the premises that should not be posited; or something of this kind is added in the conclusion: and then either that to which it is added is taken both in the premise and in the conclusion, yet in one it is added to itself and not in the other, and then there is a fallacy secundum quid et simpliciter; or something is added to one in the premise that is not placed in the conclusion, and then there is a fallacy according to ignorance of the list. |
Haec omnia patere possunt per exempla posita de istis fallaciis. Ex quibus etiam elici potest quo modo istae fallaciae ab invicem distinguuntur, ita quod quamvis fallaciae multae possunt concurrere in eodem paralogismo, tamen possibile est invenire paralogismos in quibus nullae fallaciae concurrunt exceptis fallacia accidentis et consequentis; quia ubicumque praemissae disponuntur in figura, si ibi sit fallacia consequentis, erit etiam ibi fallacia accidentis. Ad cognoscendum autem utrum in argumento facto sit fallacia vel non, inter alia documenta hoc est perutile et necessarium quod respondens ad nullum argumentum respondeat nisi opponens arguat ex certis propositionibus sub certis verbis non variatis nec transpositis nec aliquo modo mutatis, quas respondens diligenter consideret an aliqua illarum sit multiplex per aliquam fallaciam in dictione. | All this can be made clear by the examples given of these fallacies. From which it can also be inferred how these fallacies are distinguished from one another, so that although many fallacies can occur in the same paralogism, it is still possible to find paralogisms in which no fallacies occur except the fallacies of accident and consequent; because wherever the premises are arranged in a figure, if there is a fallacies of consequence there, there will also be a fallacy of accident there. But to know whether a fallacy is made in the argument or not, among other documents this is useful and necessary that the respondent should not respond to any argument unless the opponent argues from certain propositions under certain words not varied nor transposed nor changed in any way, which the respondent should carefully consider whether any of them is multiple through some fallacy in the wording. |
Deinde discutiat an tale argumentum per aliquam regulam certam et evidentem reguletur. Et tunc primo respondeat, diligenter considerans de quolibet an sit consequens vel repugnans praeconcesso, vel antecedens praenegato, ut sic consequenter semper respondeat. Et haec de fallaciis ad praesens dicta sufficiant. | Then let him discuss whether such an argument is governed by some certain and evident rule. And then let him immediately respond, carefully considering whether each is consequent or inconsistent with what is pre-granted, or antecedent to what is pre-denied, so that he always responds consistently. And let these words about fallacies suffice for the present. |
Si primo modo vel secundo: vel e converso est bonum argumentum vel non. Si sic, est fallacia consequentis; si non, est fallacia accidentis. Si sit ibi excessus terminorum, quia scilicet plura incomplexa ponuntur quam deberent, quia scilicet aliquid additur in praemissa quod non deberet poni; vel aliquid tale additur in conclusione: et tunc vel illud cui additur accipitur tam in praemissa quam in conclusione, tamen in una additur sibi et non in alia, et tunc est fallacia secundum quid et simpliciter; vel additur uni in praemissa quod non ponitur in conclusione, et tunc est fallacia secundum ignorantiam elenchi. | If in the first or second mode: or conversely, if the argument is good or not. If so, it is a fallacy of the consequent; if not, it is a fallacy of accident. If there is an excess of terms there, namely because more incomplexes are put than they should be, namely because something is added to the premises that should not be posited; or something of this kind is added to the conclusion: and then either that to which it is added is taken both in the premises and in the conclusion, yet in one it is added to itself and not in the other, and then it is a fallacy secundum quid et simpliciter; or something is added to one in the premises that is not put in the conclusion, and then it is a fallacy according to ignorance of the list. |
Haec omnia patere possunt per exempla posita de istis fallaciis. Ex quibus etiam elici potest quo modo istae fallaciae ab invicem distinguuntur, ita quod quamvis fallaciae multae possunt concurrere in eodem paralogismo, tamen possibile est invenire paralogismos in quibus nullae fallaciae concurrunt exceptis fallacia accidentis et consequentis; quia ubicumque praemissae disponuntur in figura, si ibi sit fallacia consequentis, erit etiam ibi fallacia accidentis. Ad cognoscendum autem utrum in argumento facto sit fallacia vel non, inter alia documenta hoc est perutile et necessarium quod respondens ad nullum argumentum respondeat nisi opponens arguat ex certis propositionibus sub certis verbis non variatis nec transpositis nec aliquo modo mutatis, quas respondens diligenter consideret an aliqua illarum sit multiplex per aliquam fallaciam in dictione. | All this can be made clear by the examples given of these fallacies. From which it can also be inferred how these fallacies are distinguished from one another, so that although many fallacies can occur in the same paralogism, it is still possible to find paralogisms in which no fallacies occur except the fallacies of accident and consequent; because wherever the premises are arranged in a figure, if there is a fallacies of consequence there, there will also be a fallacies of accident there. But to know whether a fallacy is made in the argument or not, among other documents this is useful and necessary that the respondent should not respond to any argument unless the opponent argues from certain propositions under certain words not varied nor transposed nor changed in any way, which the respondent should carefully consider whether any of them is multiple through some fallacy in the wording. |
Deinde discutiat an tale argumentum per aliquam regulam certam et evidentem reguletur. Et tunc primo respondeat, diligenter considerans de quolibet an sit consequens vel repugnans praeconcesso, vel antecedens praenegato, ut sic consequenter semper respondeat. Et haec de fallaciis ad praesens dicta sufficiant. | Then let him discuss whether such an argument is governed by some certain and evident rule. And then let him immediately respond, carefully considering whether each is consequent or repugnant to what is pre-granted, or antecedent to what is pre-denied, so that he always responds consistently. And let these words about fallacies suffice for the present. |
EXPLICIT TRACTATUS LOGICAE DIVISUS IN TRES PARTES ET UNAQUAEQUE PARS EST DISTINCTA PER CAPITULA. | Thus ends the Treatise on Logic Divided into Three Parts and Each Part is Distinct by Chapters. |