Authors/Ockham/Summa Logicae/Book II/Chapter 23

Latin	English
[2.23 DE CONVERSIONE PROPOSITIONUM QUAE NON SUNT MERE CATEGORICAE, CUIUSMODI SUNT EXCLUSIVAE, REDUPLICATIVAE EXCEPTIVAE ET HUIUSMODI]	Chapter 23. On the Conversion of Propositions which are not Simply Categorical, Such as Exclusives, Reduplicatives, Exceptives, etc.
Ex praedictis in duobus praecedentibus capitulis potest aliqualiter patere conversio propositionum reduplicativarum, exclusivarum, exceptivarum et aliarum in quibus panitur hoc verbum 'incipit' vel 'desinit'. Nam propositio habens exponentes habet consimilem conversionem cum suis exponentibus, et si omnes exponentes eodem modo convertantur, illa exposita eodem modo convertitur. Si autem una exponens convertatur uno modo et alia alio modo, scilicet una simpliciter et alia per accidens, tunc habebit consimilem conversionem cum conversione unius et non cum canuersione alterius.	From what has been said in the two preceding chapters, the conversion of reduplicative, exclusive, exceptive, and other propositions in which this word 'begins' or 'ends' is used can be somewhat clear. For a proposition having exponents has a similar conversion with its exponents, and if all the exponents are converted in the same way, that exponent is converted in the same way. But if one exponent is converted in one way and another in another way, namely one simply and the other accidentally, then it will have a similar conversion with the conversion of one and not with the conversion of the other.
Tamen magis in speciali videndum est de istis. Unde sciendum est quod propositio reduplicativa non convertitur in propositionem reduplicativam, sed convertitur in unam non reduplicativam, cuius subiectum erit unum aggregatum ex praedicato prioris et illo super quod cadit reduplicatio, cum reduplicatione mediante hoc pronomine 'quod'. Sicut ista 'animal in quantum homo est risibile' convertitur in istam 'aliquid, quod in quantum homo est risibile, est animal' et non in istam 'risibile, in quantum homo, est animal'. Instantia patet hic 'Sortes in quantum homo est risibilis, igitur risibile in quantum homo est Sortes', quia antecedens est verum et consequens falsum. Similiter ista 'nullum activum in quantum passivuni est activum' convertitur in istam 'igitur nihil quod est activum in quantum passivum, est activum'.	However, we must look more closely at these. Hence it should be known that a reduplicative proposition is not converted into a reduplicative proposition, but is converted into a non-reduplicative one, the subject of which will be one aggregate from the predicate of the prior and that on which the reduplication falls, with reduplication by means of the pronoun 'which'. Just as the statement 'an animal insofar as (it is) a man is able to laugh' is converted into the statement 'something, which insofar as (it is) a man, is able to laugh, is an animal' and not into the statement 'something that can laugh, insofar as it is a man, is an animal'. The instance is clear here 'Socrates insofar as he is a man is able to laugh, therefore something that can laugh insofar as it is a man is Socrates', because the antecedent is true and the consequent false. Similarly the statement 'nothing active insofar as it is passive is active' is converted into the statement 'therefore nothing which is active insofar as it is passive is active'.
Similiter, proportionaliter, hic dictis et dictis in priori capitulo dicendum est de conversione propositionum reduplicativarum de praeterito et de futuro.	Similarly, proportionally to what has been said here and in the previous chapter, we must speak about the conversion of reduplicative propositions about the past and the future.
Circa conversionem propositionum exclusivarum est sciendum quod exclusiva non canuertitur in exclusivam. Non enim sequitur 'tantum animal est homo, igitur tantum homo est animal', sed ipsa convertitur in universalem, sicut sequitur 'tantum animal est homo, igitur omnis homo est animal'. Similiter sequitur 'tantum homo non currit, igitur omne non currens est homo'.	Regarding the conversion of exclusive propositions, it should be noted that an exclusive is not converted into an exclusive. For it does not follow that 'only an animal is a man, therefore only a man is an animal', but it is converted into a universal, just as it follows that 'only an animal is a man, therefore every man is an animal'. Similarly, it follows that 'only a man does not run, therefore everything that does not run is a man'.
Et sicut dictum est de conversione propositionum de praeterito et de futuro, ita dicendum est de conversione talium exclusivarum de praeterito et de futuro. Unde non sequitur 'omne album fuit Sortes', subiecto accepto pro eo quod est, 'igitur tantum Sortes fuit albus'; nam posito quod nihil sit modo album nisi Sortes et quod multi alii fuerunt albi, antecedens est verum et consequens falsum. Et ideo non convertitur isto modo sed sic 'omne album fuit Sortes, igitur tantum Sortes est albus'. Non tamen est conversio mutua. Et sicut dictum est de ista, ita proportionaliter dictis in priori capitulo dicendum est de aliis exclusivis.	And as was said about the conversion of propositions about the past and the future, so must we say about the conversion of such exclusives about the past and the future. Hence it does not follow that 'every white thing was Socrates', with the subject taken for what it is, 'therefore only Socrates was white'; for, supposing that nothing is white except Socrates and that many others have been white, the antecedent is true and the consequent false. And therefore, it is not converted in this way, but thus: 'every white thing was Socrates, therefore only Socrates is white'. However, there is no mutual conversion. And as was said about this, so must we say about the other exclusives in proportion to what was said in the previous chapter.
Circa conversionem propositionum exceptivarum est sciendum quod exceptiva non convertitur in exceptivam. Non enim sequitur 'omnis homo praeter Sortem currit, igitur aliquid currens praeter Sortem est homo', quia consequens est improprium. Sed exceptiva convertitur in unam non-exceptivam, cuius subiectum erit unum aggregatum ex praedicato exceptivae et parte extra capta, mediante hoc toto 'quod non est', sic 'omnis homo praeter Sortem currit, igitur aliquod currens, quod non est Sortes, est homo'. Et ista 'nullus homo praeter Sortem currit' convertitur in istam 'nullum currens, quod non est Sortes, est homo'.	Regarding the conversion of exceptive propositions, it should be noted that the exceptive is not converted into an exceptive. For it does not follow that 'every man runs except Socrates, therefore something running except Socrates is a man', because the consequent is improper. But the exceptive is converted into a non-exceptive, the subject of which will be one aggregate from the predicate of the exceptive and the part taken outside, through this whole phrase 'which is not', thus 'every man runs except Socrates, therefore something running that is not Socrates is a man'. And the statement 'no man runs except Socrates' is converted into the statement 'nothing running that is not Socrates is a man'.
Circa conversionem prapasitionum in quibus ponuntur haec verba 'incipit', 'desinit' est sciendum quod non convertuntur in prapositiones consimiles. Non enim sequitur 'aliquis homo incipit esse albus, igitur aliquod album incipit esse homo', sed debent tales propositiones sic converti 'aliquis homo incipit esse albus, igitur aliquid, quod incipit esse album, est homo'. Et ita est de aliis.	Regarding the conversion of prepositions in which the words 'begins' and 'ends' are placed, it should be noted that they are not converted into similar prepositions. For it does not follow that 'some man begins to be white, therefore something white begins to be a man', but such propositions should be converted thus 'some man begins to be white, therefore something that begins to be white is a man'. And so it is with the others.
Ex praedictis possunt elici modi conversionum quarumcumque propositionum de inesse, sive sunt de praesenti sive de praeterito sive de futuro, sive etiam sint categoricae non aequivalentes propositionibus hypotheticis sive sint aequivalentes eis.	From the things said above, modes of conversion of any propositions of inherence can be derived, whether they are about the present, the past, or the future, or whether they are categorical and not equivalent to hypothetical propositions or whether they are equivalent to them.