LESSON XIII

Truth and Falsity in Opposed Singular Propositions About the

Future in Contingent Matter

             18a 28 In enunciations about that which is or has taken place, the affirmation or the negation must be true or false. And in enunciations of universals as universal, one is always true and the other false, and also in enunciations of singulars, as has been said; but in enunciations of universals not taken universally, it is not necessary that one be true and the other false. We have already spoken of these.

             However, in enunciations about future singular things the case is not the same.

             18a 34 For if every affirmation or negation is true or false, then everything belongs or does not belong to a thing necessarily;

             18a 35 for if one person says a thing will be such, and another says it will not be this very thing, clearly one of them must be speaking the truth if every affirmation is true or false. For it will not both belong and not belong to the thing simultaneously in such cases.

             18a 39 For if it is true to say that a thing is white or is not white, it must necessarily be white or not white. And if it is white or not white, it was true to affirm or deny it. And if it does not belong to it, it is false to say that it does, and if it is false to say that it does, then it does not belong to it. Consequently, it is necessary that either the affirmation or negation be true. If this is so, then nothing either is, or takes place fortuitously or indeterminately in relation to two alternatives, or will be or will not be; but everything takes place of necessity and is not indeterminate to either of two alternatives (for the supposition is that either the one who affirms it or the one who denies it is speaking the truth). Whereas if everything does not take place of necessity, it could take place or not take place as well, for what is indeterminate to either of two alternatives happens or will happen no more in this way than not.

             18b 9 Furthermore, on such a supposition, if something is now white, it was true to say formerly that it will be white; therefore it was always true to say of anything that has taken place that it will be. But if it was always true to say that it is or will be, it is not possible for this not to be, nor that it will not be; and when a thing cannot not take place, it is impossible that it not take place, and when it is impossible that it not take place, it is necessary that it take place; all things that will be, then, must necessarily take place. Therefore, nothing will be indeterminate to either of two alternatives, nor fortuitous; for if it were fortuitous it would not take place of necessity.

             18b 17 But still it is not possible to say that neither is true; that is, to say that a thing neither will take place nor will not take place.

             18b 18 In the first place, though the affirmation be false, the negation will not be true, and though the negation be false, the affirmation will not be true.

             18b 20 Secondly, if it is true to say that a thing is white and large, both necessarily belong to it; and if they will belong to it the next day, they will necessarily belong to it the next day. But if a thing neither will be nor will not be tomorrow, it would not be indeterminate to either of two alternatives. For example, in the case of a naval battle, it would be necessary that the naval battle neither take place nor not take place tomorrow.

             1. Now that he has treated opposition of enunciations and has shown the way in which opposed enunciations divide truth and falsity, the Philosopher inquires about a question that might arise, namely, whether what has been said is found to be so in all enunciations or not. And first he proposes a dissimilarity in enunciations with regard to dividing truth and falsity, then proves it where he says, For if every affirmation or negation is true or false, etc.

             2. In relation to the dissimilarity which he intends to prove we should recall that the Philosopher has given three divisions of the enunciation. The first was in relation to the unity of enunciation, and according to this it is divided into one simply and one by conjunction; the second was in relation to quality, and according to this it is divided into affirmative and negative; the third was in relation to quantity, and according to this it is either universal, particular, indefinite, or singular.

             3. Here he treats of a fourth division of enunciation, a division according to time. Some enunciations are about the present, some about the past, some about the future. This division could be seen in what Aristotle has already said, namely, that every enunciation must have a verb or a mode of a verb, the verb being that which signifies the present time, the modes with past or future time.

             In addition, a fifth division of the enunciation can be made, a division in regard to matter. It is taken from the relationship of the predicate to the subject. If the predicate is per se in the subject, it will be said to be an enunciation in necessary or natural matter. Examples of this are "Man is an animal" and "Man is risible." If the predicate is per se repugnant to the subject, as excluding the notion of it, it is said to be an enunciation in impossible or remote matter; for example, the enunciation "Man is an ass." If the predicate is related to the subject in a way midway between these two, being neither per se repugnant to the subject nor per se in it, the enunciation is said to be in possible or contingent matter.

             4. Given these differences of enunciations, the judgment of truth and falsity is not alike in all. Accordingly, the Philosopher says, as a conclusion from what has been established:: In enunciations about that which is, i.e., in propositions about the present, or has taken place, i.e., in enunciations about the past, the affirmation or the negation must be determinately true or false. However, this differs according to the different quantity of the enunciations. In enunciations in which something is universally predicated of universal subjects, one must always be true, either the affirmative or negative, and the other false, i.e., the one opposed to it. For as was said above, the negation of a universal enunciation in which something is predicated universally, is not the universal negative, but the particular negative, and conversely, the universal negative is not directly the negation of the universal affirmative, but the particular negative. According to the foregoing, then, one of these must always be true and the other false in any matter whatever. And the same is the case in singular enunciations, which are also opposed contradictorily. However, in enunciations in which something is predicated of a universal but not universally, it is not necessary that one always be true and the other false, for both could be at once true.

             5. The case as it was just stated has to do with propositions about the past or the present. Enunciations about the future that are of universals taken either universally or not universally are also related in the same way in regard to oppositions. In necessary matter all affirmative enunciations are determinately true; this holds for enunciations in future time as well as in past and present time; and negative enunciations are determinately false. In impossible matter the contrary is the case. In contingent matter, however, universal enunciations are false and particular enunciations true. This is the case in enunciations about the future as well as those of the past and present. In indefinite enunciations, both are at once true in future enunciations as well as in those of the present or the past.

             6. In singular future enunciations, however, there is a difference. In past and present singular enunciations, one of the opposites must be determinately true and the other false in any matter whatsoever, but in singulars that are about the future, it is not necessary that one be determinately true and the other false. This holds with respect to contingent matter; with respect to necessary and impossible matter the rule is the same as in enunciations about the present and the past.

             Aristotle has not mentioned contingent matter until now because those things that take place contingently pertain exclusively to singulars, whereas those that per se belong or are repugnant are attributed to singulars according to the notions of their universals.

             Aristotle is therefore wholly concerned here with this question: whether in singular enunciations about the future in contingent matter it is necessary that one of the opposites be determinately true and the other determinately false.

             7. He proves that there is a difference between these opposites and the others where he says, For if every affirmation or negation is true or false, etc. First he proves it by showing that the opposite position leads to what is unlikely; secondly, he shows that what follows from this position is impossible, where he says, These absurd consequences and others like them, etc. In his proof he first shows that in enunciations about future singulars, truth cannot always be determinately attributed to one of the opposites, and then he shows that both cannot lack truth, where he says, But still it is not possible to say that neither is true, etc. He gives two arguments with respect to the first point. In the first of these he states a certain consequence, namely, that if every affirmation or negation is determinately true or false, in future singulars as in the others, it follows that all things must determinately be or not be.

             He proves this consequence where he says, wherefore, if one person says, etc., or as it is in the Greek, for if one person says something will be, etc. Let us suppose, he argues, that there are two men, one of whom says something will take place in the future, for instance, that Socrates will run, and the other says this same thing will not take place. If the foregoing position is supposed--that in singular future enunciations one of them will be true, either the affirmative or the negative--it would follow that only one of them is saying what is true, because in singular future propositions both cannot be at once true, that is, both the affirmative and the negative. This occurs only in indefinite propositions. Moreover, from the fact that one of them must be speaking the truth, it follows that it must determinately be or not be. Then he proves this from the fact that these two follow upon each other convertibly, namely, truth is that which is said and which is so in reality. And this is what he manifests when he says that, if it is true to say that a thing is white, it necessarily follows that it is so in reality; and if it is true to deny it, it necessarily follows that it is not so. And conversely, for if it is so in reality, or is not, it necessarily follows that it is true to affirm or deny it. The same convertibility is also evident in what is false, for if someone lies, saying what is false, it necessarily follows that in reality it is not as he affirms or denies it to be; and conversely, if it is not in reality as he affirms or denies it to be, it follows that in affirming or denying it he lies.

             8. The process of Aristotle's reasoning is as follows. If it is necessary that every affirmation or negation about future singulars is true or false, it is necessary that everyone who affirms or denies, determinately says what is true or false. From this it follows that it is necessary that everything be or not be. Therefore, if every affirmation or negation is determinately true, it is necessary that everything determinately be or not be. From this he concludes further that all things are of necessity. This would exclude the three kinds of contingent things.

             9. The three kinds of contingent things are these: some, the ones that happen by chance or fortune, happen infrequently; others are indeterminate to either of two alternatives because they are not inclined more to one part than to another, and these proceed from choice; still others occur for the most part, for example, men becoming gray in old age, which is caused by nature. If, however, everything took place of necessity, there would be none of these kinds of contingent things. Therefore, Aristotle says, nothing is with respect to the very permanence of those things that are contingently permanent; or takes place with respect to those that are caused contingently; by chance with respect to those that take place for the least part, or infrequently; or is indeterminate to either of two alternatives with respect to those that are related equally to either of two, i.e., to being or to nonbeing, and are determined to neither of these, which he signifies when he adds, or will be, or will not be.

             For of that which is more determined to one part we can truly and determinately say that it will be or will not be, as for example, the physician truly says of the convalescent, "He will be restored to health," although perchance by some accident his cure may be impeded. The Philosopher makes this same point when he says in II De generatione, "A man about to walk might not walk." For it can be truly said of someone who has the determined intention to walk that he will walk, although by some accident his walking might be impeded. But in the case of that which is indeterminate to either of two, it cannot determinately be said of it either that it will be or that it will not be, for it is proper to it not to be determined more to one than to another.

             Then he manifests how it follows from the foregoing hypothesis that nothing is indeterminate to either of two when he adds that if every affirmation or negation is determinately true, then either the one who affirms or the one who denies must be speaking the truth. That which is indeterminate to either of two is therefore destroyed, for if there is something indeterminate to either of two, it would be related alike to taking place or not taking place, and no more to one than to the other.

             It should be noted that the Philosopher is not expressly excluding the contingent that is for the most part. There are two reasons for this. In the first place, this kind of contingency still excludes the determinate truth of one of the opposite enunciations and the falsity of the other, as has been said. Secondly, when the contingent that is infrequent, i.e., that which takes place by chance, is removed, the contingent that is for the most part is removed as a consequence, for there is no difference between that which is for the most part and that which is infrequent except that the former fails for the least part.

             10. When he says, Furthermore, on such a supposition, if something is now white, it was true to say formerly that it will be white, etc., he gives a second argument to show the dissimilarity of enunciations about future singulars. This argument is by reduction to the impossible. If truth and falsity are related in like manner in present and in future enunciations, it follows that whatever is true of the present was also true of the future, in the way in which it is true of the present. But it is now determinately true to say of some singular that it is white; therefore formerly, i.e., before it became white, it was true to say that this will be white. Now the same reasoning seems to hold for the proximate and the remote. Therefore, if yesterday it was true to say that this will be white, it follows that it was always true to say of anything that has taken place that it will be. And if it is always true to say of the present that it is, or of the future that it will be, it is not possible that this not be, or, that it will not be. The reason for this consequence is evident, for these two cannot stand together, that something truly be said to be, and that it not be; for this is included in the signification of the true, that that which is said, is. If therefore that which is said concerning the present or the future is posited to be true, it is not possible that this not be in the present or future. But that which cannot not take place signifies the same thing as that which is impossible not to take place. And that which is impossible not to take place signifies the same thing as that which necessarily takes place, as will be explained more fully in the second book. It follows, therefore, that all things that are future must necessarily take place. From this it follows further, that there is nothing that is indeterminate to either of two or that takes place by chance, for what happens by chance does not take place of necessity but happens infrequently. But this is unlikely. Therefore the first proposition is false, i.e., that of everything of which it is true that it is, it was determinately true to say that it would be.

             11. For clarification of this point, we must consider the following. Since "true" signifies that something is said to be what it is, something is true in the manner in which it has being. Now, when something is in the present it exists in itself, and hence it can be truly said of it that it is. But as long as something is future, it does not yet exist in itself, but it is in a certain way in its cause, and this in a threefold way. It may be in its cause in such a way that it comes from it necessarily. In this case it has being determinately in its cause, and therefore it can be determinately said of it that it will be. In another way, something is in its cause as it has an inclination to its effect but can be impeded. This, then, is determined in its cause, but changeably, and hence it can be truly said of it that it will be but not with complete certainty. Thirdly, something is in its cause purely in potency. This is the case in which the cause is as yet not determined more to one thing than to another, and consequently it cannot in any way be said determinately of these that it is going to be, but that it is or is not going to be.

             12. Then Aristotle says, But still it is not possible to say that neither is true, etc. Here he shows that truth is not altogether lacking to both of the opposites in singular future enunciations. First he says that just as it is not true to say that in such enunciations one of the opposites is determinately true, so it is not true to say that neither is true; as if we could say that a thing neither will take place nor will not take place.

             Then when he says, In the first place, though the affirmation be false, etc., he gives two arguments to prove his point. The first is as follows. Affirmation and negation divide the true and the false. This is evident from the definition of true and false, for to be true is to be what in fact is, or not to be what in fact is not; and to be false is to be what in fact is not, or not to be what in fact is. Consequently, if the affirmation is false, the negation must be true, and conversely. But if the position is taken that neither is true, the affirmation, "This will be" is false, yet the negation is not true; likewise the negation will be false and the affirmation not be true. Therefore, the aforesaid position is impossible, i.e., that truth is lacking to both of the opposites.

             The second argument begins where he says, Secondly, if it is true to say that a thing is white and large, etc. The argument is as follows. If it is true to say something, it follows that it is. For example, if it is true to say that something is large and white, it follows that it is both. And this is so of the future as of the present, for if it is true to say that it will be tomorrow, it follows that it will be tomorrow. Therefore, if the position that it neither will be or not be tomorrow is true, it will be necessary that it neither happen nor not happen, which is contrary to the nature of that which is indeterminate to either of two, for that which is indeterminate to either of two is related to either; for example, a naval battle will take place tomorrow, or will not. The same unlikely things follow, then, from this as from the first argument.