27: On the Conversion of de contingenti Propositions
27: On the Conversion of de contingenti Propositions Next we must look into the conversion of de contingenti propositions. And it should first be noted that in this chapter 'contin- 'gent' should always be taken for what is contingent with respect to truth and falsity. Thus, only a proposition which is neither necessary nor impossible is called contingent. Now since such a proposition has two sorts of conversion, one in the terms and one through opposite qualities, we should deal first with the former and then with the latter.
Now it should first be noted that de contingenti propositions, taken in the sense of composition, and propositions equivalent to those so taken are converted just as their non-modal counterparts are converted, as long as those non-modal counterparts are converted simply. The reason for this is that such a conversion holds in accord with the following rule:
'If one of two interchangeable propositions is contingent, the other is contingent'. This rule is always true. Therefore, this is valid: 'That a man is white is contingent; therefore that a white thing is a man is contingent'. Similarly, this follows: "That God creates is contingent; therefore that a being which creates is God is contingent'. And so a particular affirmative as well as a universal negative de contingenti proposition, taken in the sense of composition, is converted simply. Similarly, this is valid: 'This is contingent: "No man is white"; therefore this is contingent: "No white thing is a man"', and so on for the others.
However, when its non-modal counterpart is converted only accidentally and not simply, then a de contingenti proposition in the sense of composition is not converted in the terms. For such a conversion can hold only in accord with this mediating proposition: 'If the antecedent is contingent, the consequent is contingent'. But this is simply false, since what is necessary follows from what is contingent. Therefore, this does not follow:
'That every man is white is contingent; therefore that some white thing is a man is contingent'—just as this does not follow: 'That every actually existing substance is God is contingent; therefore
Conversion of de contingenti Propositions that God is an actually existing substance is contingent'. For in this latter case the antecedent is true and the consequent false.
For the proposition 'Every actually existing substance is God' is contingent, since it can be true and it can be false. And yet the proposition 'God is an actually existing substance' is necessary.
On the other hand, if a de contingenti proposition is taken in the sense of division or is equivalent to a proposition so taken, then if that proposition has for its subject a common term or something which includes a common term (e.g. 'this white thing', 'this man', 'this donkey'), or if it has for its subject a participle or some equivalent thereof, then the proposition must be distinguished. For the subject can supposit either for those things which are such-and-such or for those things which are contingently suchand-such. If the subject of such a proposition is taken in the first way, then even if the subject is a proper name or demonstrative pronoun, the proposition is not converted into the same type of de contingenti proposition. Rather, it is converted into a nonmodal proposition and into a de possibili proposition, where the subject of the consequent is taken with the additional phrase
'which is contingently .. .'.
The first point is obvious, namely, that it is not converted into the same type of de contingenti proposition. For this does not follow: 'God is contingently a being which creates; therefore a being which creates is contingently God'; nor does this follow:
'therefore something which is contingently a creator is contingently God'. For this latter proposition is incompatible with the following true proposition: 'Something which contingently creates is necessarily God'—and, consequently, it is not contingently God.
The second point, namely, that such a proposition is converted into a non-modal proposition in the way indicated above, is clear.
For this is valid: 'God is contingently a being which creates; therefore something which is contingently a being which creates is
'This conversion can be proven. For if 'God is contingently a beirig which creates' is true, then it is obvious that both of these propositions are true: 'This is God', referring to that for which the subject of the de contingenti proposition supposits, and 'This
Conversion of de contingenti Propositions is contingently a being which creates'. But then this follows by means of an expository syllogism: 'This is God; this is contingently a being which creates; therefore something which is contingently a being which creates is God'. Consequently, the proposition 'God is contingently a being which creates' is not compatible with the opposite of the proposition 'Something which is contingently a being which creates is God'. And, consequently, the latter follows from the former. And so this conversion is proven by means of an expository syllogism. And just as this one is proven by means of an expository syllogism, so too many of the previous conversions, the proofs of which were omitted, are proven in the same way.
Now sucha proof is sufficient, since an expository syllogism is evident in itself and does not require any further proof. Thus, those who deny such a syllogism no matter what its material element is commit a serious mistake, unless they can show that there is in such a syllogism a fallacy of equivocation, or of amphiboly, or of composition and division, or of accent, or of figure of speech, or of relative and absolute, or that there is an ignoratio elenchi or a petitio principii. But there cannot be, as many claim, a fallacy of accident in such a syllogism.
And since expository syllogisms, which are evident in themselves, are frequently denied by modern theologians—and so one should not argue with such people, since they deny what is known in itself—I will digress somewhat from what I proposed to do and offer some examples in which a syllogism is not expository even though it seems to be.
Hence, this is not an expository syllogism: 'This animal is a dog (canis); this animal is not a celestial constellation; therefore a celestial constellation is not Canis'. The reason is that both the major premise and the conclusion must be distinguished as equivocal.
Similarly, this is not an expository syllogism: 'Iste vellet se accipere pugnantes; iste vellet vincere; igitur qui vellet vincere, vellet se accipere pugnantes'. The reason is that the major premise must be distinguished as amphibolous, as is made clear in other places.!
Again, this is not an expository syllogism: 'This is false: '""You are a donkey"; this is true if it is necessary: "You are a donkey"; therefore something true, if it is necessary, is false'. For the xninor
Conversion of de contingenti Propositions premise and the conclusion have to be distinguished with respect to composition and division.
Again, this is not an expository syllogism: 'Iste vult pendere; iste non vult pendere; igitur qui vult pendere, non vult pendere'.
For the propositions must be distinguished with respect to accent."
Similarly, this is not an expository syllogism: 'Sortes est albus; Sortes est animal; igitur animal est albus'. Rather, in this case there is a fallacy of a figure of speech. For the samereason this is not an expository syllogism: 'Iste homo est sanus; iste homo est substantia; igitur aliqua substantia est sanus'.°
Similarly, this is not an expository syllogism: 'Socrates is not the son of Plato; Socrates is a father; therefore some father is not a son'. Instead, there is an ignoratio elenchi in this case.
Likewise, this is not an expository syllogism: 'Socrates is white with respect to his teeth; Socrates is black; therefore something black is white'. Here there is a fallacy of relative and absolute.
Nor is this a probative expository syllogism: 'Socrates is hot; Socrates is productive of heat; therefore a thing productive of heat is hot'. For in this case there is a petitio principii. And so the argument does not prove the conclusion, even though its form is valid.* And just as these examples, which appear to be expository syllogisms and are not, contain some obvious defect other thana fallacy of accident, so it is with others.
Hence, it should be noted that it is a general rule that when the propositions involved are just present-tense non-modal propositions, and when they are arranged in a syllogistic figure without any addition or subtraction on the part of the subject and the predicate, then there is never a fallacy of accident in such an argument—just as there is never a fallacy of accident in an argument arranged in the first mode of the first figure. This will be shown below.> In the same way, when an argument can be reduced to such an expository syllogism—either by conversion or per impossibile or by using equivalent propositions—then there is no fallacy of accident.® It should be noted, however, that for a syllogism to be expository it is not sufficient that one argue by using a demonstrative pronoun or the proper name of some singular thing as the middle
Conversion of de contingenti Propositions term. Rather, besides this it is necessary that the thing referred to or designated by such a proper name is not really more than one distinct thing. For this reason the following is not an expository syllogism: 'This essence (referring to the divine essence) is the Father; this essence is the Son; therefore the Son is the Father'.
The reason is that the essence in question is more than one distinct thing. Thus, in such a paralogism there is a fallacy of consequent, although there is also a fallacy of accident in this case.
Now no defect can be pointed to in this syllogism: 'This is God; this is contingently a being which creates; therefore a being which is contingently a being which creates is God'. Therefore, it is clear that it is an evident expository syllogism. Consequently, it has been sufficiently proven that 'God contingently creates' is converted into 'Something which contingently creates is God'.
From this it is also clear that the proposition in question is converted into the following de possibili proposition: 'Something which contingently creates is possibly God'. For a non-modal proposition always formally entails its de possibili counterpart.
Now if the subject of such a de contingenti proposition is a demonstrative pronoun or a proper name, then the proposition is converted just as before, namely, into a non-modal proposition and into a de possibili proposition. However, if the subject of such a de contingenti proposition is taken for those things which are contingently such-and-such, then the proposition is converted into the same type of de contingenti proposition, where the subject of the consequent is taken for what is contingently such-andsuch. Hence, this is valid: 'Some man is contingently running; therefore some running thing is contingently a man'—as long as the subject of each proposition is taken for that which is contingently such-and-such. For then the consequent has this sense:
'Something which is contingently running is contingently a man'.
The conversion is valid, since the opposite of the consequent is incompatible with the antecedent, namely, this is not compatible with the antecedent: 'Nothing which is contingently running is contingently a man'. For if 'Something which is contingently a man is contingently running' is true, then let that thing be A. In that case both of the following are true: 'A is contingently a man' and 'A is contingently running'. From these propositions I argue
Conversion of de contingenti Propositions as follows: 'A is contingently a man; A is contingently running; therefore something which is contingently running is contingently a man'. This conclusion is the contradictory of the proposition noted above. Therefore, that proposition cannot stand. And so this clearly follows: 'Something which is contingently a man is contingently running; therefore something which is contingently running is contingently a man'. And so this consequence is valid:
'Some man is contingently running; therefore some running thing is contingently a man'—as long as the subject of each proposition is taken for that which is contingently such-and-such.
Now someone might object that if this were so, then the following would be valid: 'God contingently creates; therefore something which creates is contingently God'. For this follows: 'A is contingently God; A contingently creates; therefore something which contingently creates is contingently God'—just as it was argued in the above example.
It should be replied that this last syllogism is valid, but that it still does not prove the conversion in question. The reason is that the proposition 'God contingently creates' does not yield the propositions 'A is contingently God' and 'A contingently creates'. For these two propositions are not required for the truth of the proposition in question in the way that two such propositions are required for the truth of 'Some man is contingently running', when the subject is taken for those things which are contingently men. Therefore, the one conversion is proved by the one expository syllogism and yet the other conversion is not proved by the other syllogism. Hence, if the subject of a de contingenti proposition is a demonstrative pronoun or a proper name, then the proposition is not converted into the same type of de contingenti proposition. Nor can its subject be taken in that way, namely, for what is contingently suchand-such.
It should be noted, however, that the above distinction with respect to de contingenti, de possibili, past-tense and futuretense propositions should be understood in this way: either the subject is taken for what is such-and-such, etc., or it is asserted that it is taken for what is such-and-such or for what is contingently such-and-such or for what was such-and-such,