8: How to Find Out when a Proposition, One of Whose Extremes is in an Oblique Case, is True or False
8: How to Find Out when a Proposition, One of Whose Extremes is in an Oblique Case, is True or False Now what has been said above is not sufficient for finding out when a 'proposition, one of whose extremes is an oblique term, is true or false. Rathér, on this matter it is necessary to have special rules. Here are some useful grammatical rules, which I will just
; Hence, it should be noted that just as in an affirmative proposition in which both terms are in the nominative case, for the truth of the proposition it is required that the subject and predicate supposit for the same thing, so too sometimes for the truth of a proposition in which one term is oblique, it is required that the subject and predicate not supposit for the same thing or that they not supposit for all the same things. Still, sometimes they can supposit for the same thing, depending on differences among the words and among the rules for an oblique case. Hence, when the oblique case has the force of possession, then for the truth of the proposition it is required that the subject and predicate supposit for distinct things, although this is not always sufficient.
Therefore, 'Socrates belongs to Socrates' is false, and yet 'Some donkey beiongs to Socrates' can be true. And just as it is with this case, so it is with many others. But sometimes the proposition can be true despite the fact that the subject and predicate supposit for the same thing, or despite the fact that the nominative term and the oblique term supposit for the same thing.
For example, 'Socrates sees Socrates' is true. And the same thing can happen in many other cases. And in these cases it is not easy to give a general and firm rule.
9: What is Required for the Truth of Modal Propositions After non-modal propositions' we must deal with modal propositions. And it should first be noted that sometimes a proposition
What is Required for the Truth ofModal Propositions is called modal because the dictum of the proposition is taken with such a mode. This is clear in the following cases: 'That every man is an animal is necessary', 'That every man is running is contingent', '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 for the others. However, some propositions are called modal in which the mode occurs without such a dictum of a proposition.
A modal proposition of the first type must always be distinguished with respect to composition and division. In the sense of composition it is always asserted that such a mode is truly predicated of the proposition corresponding to the dictum in question.
For example, by means of 'That every man is an animal is necessary' it is asserted that the mode 'necessary' is truly predicated of the proposition 'Every man is an animal', the dictum of which is 'That every man is an animal'. For something is called the dictum of a proposition when the terms of the proposition are taken in the accusative case and the verb in the infinitive mood.? However, the sense of division of such a proposition is always equipollent to a proposition taken with a mode and without such a dictum. For example, 'That every man is an animal is necessary' in the sense of division is equipollent to 'Every man is of necessity (or necessarily) an animal'. Similarly, 'That Socrates is an animal is known' in the sense of division is equipollent to 'Socrates is known to be an animal'—and so on for the others.
Hence, we should say a few things first about such propositions taken in the sense of composition and then about the others.
It should first be noted, as was just said, that by means of such a proposition it is always asserted that such a mode is truly predicated of the whole proposition which corresponds to the dictum.
Certain things follow from this. One is that a universal de necessario proposition of this sort can be necessary even though each of its singulars is contingent or false. For instance, in the sense of composition 'That every true contingent proposition is true is necessary' is true and necessary, and yet each of its singulars is false. For 'That this true contingent proposition is true is necessary', referring to any of them, is false, since this true contingent proposition can be false. But if this is so, then the singular proposition in question is false and, consequently, is not now necessary.
What is Required for the Truth of Modal Propositions But that it is necessary is asserted' by means of such a singular proposition.
Similarly, 'That every false contingent proposition is false is true' is true and necessary, and yet each of its singulars is contingent, as is obvious inductively. Likewise, sometimes such a universal proposition is impossible, and yet each singular is possible and contingent. This is clear in the case of 'That both of these are true is true', referring to two contingent propositions which are contradictories. Similarly, it is clear in the case of 'That all of these are false is true', referring to all future contingent propositions—and yet each of the singulars is contingent.?
But in response to all these examples it can be claimed that no such proposition is universal but that each such proposition is singular. For in each such proposition the subject is a single proposition or something which supposits for one proposition.
To this it should be said that we should not worry much at present about whether, strictly and properly speaking, such a proposition is universal or particular, on the one hand, or singular, on the other. For at least Aristotle calls such propositions universal and particular, as will be shown later* —and I have been speaking in the same way in the present discussion. But I do not much care whether Aristotle was in that instance speaking broadly and improperly or strictly and properly. And so I claim that a proposition is universal when the dictim of a proposition is the subject with respect to the proposition as a whole and when a common term with a universal sign is the subject with respect to the subordinate construction.S For example, in 'That every man is an animal is necessary' the phrase 'that every man is an animal' is the subject with respect to the main verb 'is', but the common term 'man' with the sign is the subject with respect to the subordinate construction. And this is sufficient for what I have claimed. Hence, if anyone wishes to hold that such propositions are properly universal, he can easily claim that it is sufficient that a common term be the subject with respect to the subordinate construction.
From these remarks it is clear that in order to know what is required for the truth of such propositions, it is sufficient to know what is required for it to be the case that some