Authors/Ockham/Summa Logicae/Book II/Chapter 9

Latin	English
[2.09 QUID REQUIRITUR AD VERITATEM PROPOSITIONUM MODALIUM]	9. What is Required for the Truth of Modal Propositions
Post propositiones de inesse dicendum est de propositionibus modalibus. Et est primo sciendum quod aliquando dicitur propositio de modo, quia accipitur dictum propositionis cum tali modo. Sicut patet de istis 'omnem hominem esse animal est necessarium', 'hominem currere est contingens', 'omnem hominem esse coloratum est verum', 'omnem hominem esse animal est per se primo modo', 'omne necessarium esse verum est scitum', 'Sortem currere est ignotum', et sic de aliis. Aliqua autem propositio dicitur modalis, in qua ponitur modus sine tali dicto propositionis.	After assertoric propositions we should talk about modal propositions. And it should first be known that sometimes a proposition is called modal because the dictum of the proposition is taken with such a mode. This is clear in the propositions: 'that every man is an animal is necessary', 'that every man is running is contingent', 'that every man is coloured is true', 'That every man is an animal is per se in the first mode', "that everything necessary is true is known', 'that Socrates is running is unknown', and so on. But a proposition is called modal in which the mode is given without such a dictum of the proposition.
Propositio modalis primo modo dicta semper est distinguenda secundum compositionem et divisionem. In sensu compositionis semper denotatur quod talis modus verificetur de propositione illius dicti, sicut per istam 'omnem hominem esse animal est necessarium' denotatur quod iste modus 'necessarium' verificetur de ista propositione 'omnis homo est animal', cuius dictum est hoc quod dicitur 'omnem hominem esse animal'; quia 'dictum propositionis' dicitur quando termini propositionis accipiuntur in accusativo casu et verbum in infinitivo modo. Sed sensus divisionis talis propositionis semper aequipollet propositioni acceptae cum modo, sine tali dicto; sicut ista 'omnem hominem esse animal est necessarium' in sensu divisionis aequilpollet isti 'omnis homo de necessitate vel necessario est animal'. Similiter ista in sensu divisionis 'Sortem esse animal est scitum' aequipollet isti 'Sortes scitur esse animal'. Et sic de aliis.	A modal proposition of the first type should always be distinguished according to composition and division. In the sense of composition it is always denoted that such a mode is verified of the proposition of that dictum, for example by 'that every man is an animal is necessary' it is denoted that the mode 'necessary' is verified of the proposition 'every man is an animal', whose dictum is 'that every man is an animal'. For something is called the dictum of a proposition when the terms of the proposition are [in Latin] taken in the accusative case and the verb in the infinitive mood. But the sense of division of such a proposition is always equipollent to a proposition taken with a mode and without such a dictum, thus 'that every man is an animal is necessary' is equipollent in the sense of division to 'every man is of necessity (or necessarily) an animal'. Likewise, 'that Socrates is an animal is known' is equipollent in the sense of division to 'Socrates is known to be an animal', and so on.
Unde de talibus modalibus acceptis in sensu compositionis primo aliqua pauca sunt dicenda, secundo de aliis.	Hence we should first say a few words about such modal propositions taken in the sense of composition, second, about the others.
Primo igitur sciendum, sicut dictum est, quod semper per talem propositionem denotatur quod talis modus verificatur de tota propositione correspondente dicto. Ex quo sequuntur aliqua. Unum est quod talis universalis de necessario poterit esse necessaria, quamvis quaelibet singularis sit contingens vel falsa. Sicut haec est vera et necessaria in sensu compositionis 'omne verum contingens esse verum est necessarium', et tamen quaelibet singularis est falsa, nam haec est falsa 'hoc verum contingens esse verum est necessarium', quocumque demonstrato, quia hoc verum contingens poterit esse falsum, et tunc illa singularis est falsa, et per consequens modo non est necessarium, quod tamen denotatur per talem singularem.	First it should be known, as was said, that always by such a proposition it is denoted that such a mode is verified of the whole proposition corresponding to the dictum. From which certain things follow. One is that a universal de necessario proposition of this sort could be necessary, although each of its singulars is contingent or false. For example, 'that every true contingent proposition is true is necessary' is true and necessary in the sense of composition , and yet each singular is false, for 'that this true contingent proposition is true is necessary', indicating any of them, is false, because this true contingent proposition could be false, and then that singular [proposition] is false and, in consequence, is not now necessary. Yet it is denoted by means of such a singular [proposition] that it is [necessary].
Similiter haec est vera et necessaria 'omne falsum contingens esse falsum est verum', et tamen quaelibet singularis est contingens, sicut inductive patet. Similiter aliquando est talis universalis impossibilis, et tamen quaelibet singularis est possibilis et contingens, sicut patet de ista 'utrumque istorum esse verum est verum', demonstratis duobus contradictoriis contingentibus. Similiter patet de ista 'quodlibet istorum' - demonstratis omnibus falsis contingentibus -- 'esse falsum est verum', et tamen quaelibet singularis est contingens.	Likewise, 'that every false contingent [proposition] is false is true' is true and necessary, and yet each singular is contingent, as is clear inductively. Likewise, sometimes such a universal proposition is impossible, and yet each singular is possible and contingent, as is clear in 'that both of these are true is true', indicating two contingent [propositions] which are contradictories. Likewise, it is clear in 'that all of these' (indicating all future contingent propositions) 'are false, is true', and yet each singular is contingent.
Sed ad omnia ista potest dici quod nulla talis propositio est universalis, sed quaelibet talis est singularis, quia in omni tali subicitur una propositio singularis vel aliquid supponens pro una propositione:	But to all these it can be said that no such proposition is universal but that each such is singular, because in each such, a singular proposition is the subject, or is something which supposits for one proposition.
Dicendum est ad hoc quod sive -- proprie et de virtute sermonis loquendo - talis propositio sit universalis vel particularis, sive quaelibet sit singularis, non est multum curandum ad praesens, quia saltem Aristoteles vocat tales propositiones universales et particulares, sicut postea ostendetur, et illo modo loquor ego in proposito. Utrum autem Aristoteles tunc loquebatur extensive et improprie vel stricte et proprie, non multum curo. Et tunc dico quod propositio illa est universalis in qua subicitur dictum propositionis respectu compositionis principalis, ita tamen quod respectu compositionis minus principalis subicitur terminus communis cum signo universali, sicut in ista 'omnem hominem esse animal est necessarium' hoc totum 'omnem hominem esse animal' subicitur respectu illius verbi indicativi modi 'est'; quia tamen respectu istius compositionis infinitivi modi 'esse' supponit hic terminus 'homo' cum signo; et hoc sufficit ad propositum. Unde qui vult tenere quod tales sunt proprie universales, potest leviter dicere quod sufficit quod subiciatur terminus communis respectu verbi infinitivi modi.	It should be said to this that whether – properly and literally speaking – such a proposition is universal or particular, or whether it is singular, is not much of a worry at present, for Aristotle, at least, calls such propositions universal and particular, just as will be shown later, and I speak in the same way in this case. But whether Aristotle was then speaking broadly and improperly or strictly and properly, I do not worry much. And then I say that the proposition in question is universal in which the dictum is the subject of the proposition with respect to the principal proposition , but so that with respect to the less principal composition a common term with a universal sign is the subject, as for example in 'that every man is an animal is necessary' the whole expression 'that every man is an animal' is the subject with respect to the verb in the infinitive mood 'is'. For nevertheless with respect to that composition of that verb in the infinitive mood 'to be', the common term 'man' with the sign ['every'] supposits, and this is sufficient for what is proposed here. Hence, whoever wants to hold that such propositions are properly universal, he can easily say that it suffices that a common term be the subject with respect to the verb in the infinitive mood.
Ex istis patet quod sufficit scire quid requiritur ad veritatem talium propositionum, sciendo quid requiritur ad hoc quod aliqua propositio sit necessaria et ad hoc quod sit contingens vel vera vel impossibilis vel scita vel ignota vel credita, et sic de aliis, de quibus omnibus pertractare nimis foret longum.	From these [points] it is clear that it suffices to know what is required for the truth of such propositions, by knowing what is required for some proposition to be necessary, or for it to be contingent, or true, or impossible, or known, or unknown, or believed, and so on for other [cases], all of which it would take too long to deal with extensively.
Tamen de propositione necessaria est sciendum quod propositio non propter hoc dicitur necessaria quia semper sit vera, sed quia est vera si sit et non potest esse falsa. Sicut haec propositio in mente 'Deus est' necessaria est, non quia semper sit vera, -- quia si non est, non est vera --, sed si sit, est vera et non potest esse falsa. Similiter haec propositio in voce 'Deus est' est necessaria, et tamen non semper est vera, quia quando non est, tunc non est vera nec falsa; sed si sit prolata, est vera et non potest esse falsa nisi termini aliter instituerentur ad significandum.	Yet concerning a necessary proposition it should be known that a proposition is called necessary not because it is always true, but because it is true if it exists and cannot be false. Thus the mental proposition 'God exists' is necessary, not because it is always true (for if it does not exist, it is not true), but [because] if it exists, it is true and cannot be false. Likewise, the spoken proposition 'God exists' is necessary, and yet it is not always true, becauses when it does not exist, then it is neither true nor false. But if it is uttered, then it is true and cannot be false, unless the terms were assigned to signify in another way.
Proportionaliter debet dici de propositione impossibili, quod est illa quae si sit, est falsa, non tamen est falsa nisi sit propositio. Et ita, proportionaliter, est de propositione contingenti. Sed ad hoc quod propositio sit scita vel credita, et sic de aliis, plus requiritur. Sed quid requiritur, pertinet ad librum Posteriorum et ad alios libros.	Something proportionate ought to be said of an impossible proposition, which is one that, if it exists, is false , and yet is not false unless it is a proposition. And so, proportionately, it is for a contingent proposition. But for a proposition to be known or believed, and so on, more is required. But what is required pertains to the book of the Posterior Analytics and to other books.