Lives of the Eminent Philosophers
Page 41
61 A conception is a figment of thought, and though it is neither an actual something nor an actual attribute, it is a quasi-something and a quasi-attribute like the image of a horse that arises in the absence of a horse.
A species is what is comprised under a genus, as Man is comprised under Animal. The most generic thing of all is the genus that has no genus, like Being; and the most specific thing of all is the species that has no species, like Socrates.
Division is the dissection of a genus into its proximate species, for example, “Among the animals, some are rational and others nonrational.” Division by dichotomy dissects the genus into species by contrary qualities, for example, by means of negation: “Among the beings, some are good and others not good.” Subdivision is the division of a division, as when we say, “Among the beings, some are good and others not good; and among the not good, some are bad and others indifferent.”
62 Partition, according to Crinis,89 is the classification of genus into topics, for example, “Of the good things, some are mental and some are physical.”
Ambiguity occurs when an expression, properly and strictly and in accordance with the same usage, signifies two or more different things, so that at one and the same time the same expression can be taken in several different ways; for example: AULETRISPEPTOKE.90 For it can signify “a house has fallen three times” (aule tris peptoke) or “a flute girl has fallen” (auletris peptoke).
Dialectic, as Posidonius says, is the branch of knowledge concerned with what is true, what is false, and what is neither false nor true. Chrysippus says that it is concerned with signifiers and things signified. This, then, is what the Stoics say in their theory of voice.
63 To the topic of things in the sense of things signified is assigned the account of sayables, including those that are complete in themselves, as well as premises and syllogisms, and the account of incomplete expressions and predicates, both direct and reversed.
By “sayable” they mean what subsists in accordance with a rational impression. Among sayables the Stoics say that some are complete and others incomplete. The incomplete ones are those that have an incomplete enunciation, for example, “writes.” For we inquire, “Who?” The complete sayables are those in which the enunciation is complete, for example, “Socrates writes.” Hence among incomplete sayables are ranged all predicates, whereas among the complete are ranged propositions, syllogisms, questions, and inquiries.
Philosopher, by Albert Tucker, 1939. Oil on cardboard, 45.7 x 51.5 cm.
64,65 The predicate is what is said of a subject, or a thing that is linked to one or more subjects, as Apollodorus and his followers say, or an incomplete sayable joined with a nominative case in order to generate a proposition. Among the predicates, some are happenings, <…> for example, “to sail through the rock.” Some predicates are direct, some reversed, and still others neither. Direct predicates are constructed with one of the oblique cases to generate a predicate, like “hears,” “sees,” and “converses with.” Reversed predicates are constructed with the passive voice, like “(I) am heard” and “(I) am seen.” Some correspond to neither of these, such as “thinks” and “walks.” Reflexive predicates are those that, though classed among the reversed, are nevertheless activities of the subject, like “has his hair cut”; for he who has his hair cut includes himself in the activity. The oblique cases are the genitive, the dative, and the accusative.91
A proposition is that which is true or false, or a complete thing that can be affirmed on its own, as Chrysippus says in his Dialectical Definitions: “A proposition is that which can be denied or affirmed on its own,” for example, “It is day” or “Dion is walking.” The word for proposition (axioma) comes from the verb axiousthai, which means “to affirm or to deny.” For one who says, “It is day,” seems to affirm that it is day. And if it is day, the proposition being advanced is true; if not, it is false.
66 Propositions differ from questions, inquiries, imperatives, oaths, prayers, hypotheses, vocatives, and quasi-propositions. For a proposition is what we affirm when we speak, and is either true or false. A question is a thing that is complete in itself, like a proposition, but requiring an answer, for example, “Is it day?” This is neither true nor false; hence “It is day” is a proposition, while “Is it day?” is a question. An inquiry is a thing to which one cannot reply with a gesture, as one can nod “yes” to a question; instead it requires an answer in words, “He lives in such and such a place.”
67 An imperative is a thing we use when we give an order, for example,
As for you, go to the waters of Inachus.92
An oath is a thing <…> A vocative is a thing we use when addressing someone, for example:
Most glorious son of Atreus, Agamemnon, lord of men.93
A quasi-proposition is that which has the form of a proposition, but because of a heightened or emotional tone in one of its parts falls outside the class of propositions, for example:
A thing of beauty is the Parthenon!
How like to Priam’s sons94 is the cowherd!
68 There is also a dubitative thing, different from a proposition, which one would use when at a loss,
Can it be that life and pain are in some way akin?95
But questions, inquiries, and the like are neither true nor false, whereas propositions are always true or false.
69 Among the propositions, some are simple, some nonsimple, as the followers of Chrysippus, Archedemus, Athenodorus, Antipater, and Crinis say. Simple ones are those that do not consist of a doubled proposition or of more than one proposition, for example, “It is day.” Nonsimple ones are those that consist of a doubled proposition or of more than one proposition. Thus they may consist of a doubled proposition, for example, “If it is day,
Among the simple propositions are included the negative, the denying, the privative, the affirmative, the demonstrative, and the indefinite; among the nonsimple are included the conditional, the affirmative conditional, the conjunctive, the disjunctive, the causal, the comparative that indicates the more, and the comparative that indicates the less. <…> and
70 A denying proposition consists of a denying particle and a predicate, for example, “No one is walking.” A privative proposition consists of a privative particle and a potentially complete proposition, for example, “This one is unkind.” An affirmative proposition consists of a noun in the nominative case and a predicate, for example, “Dion is walking.” A demonstrative proposition consists of a demonstrative in the nominative case and a predicate, for example, “This one is walking.” An indefinite proposition consists of an indefinite particle or indefinite particles and a predicate, for example, “Someone is walking” and “He is in motion.”
71,72,73 Among the nonsimple propositions, a conditional, as Chrysippus says in his Dialectics and Diogenes in his Art of Dialectic, is constructed by means of the conditional conjunction “if.” This conjunction declares that the second follows from the first, for example, “If it is day, it is light.” An affirmative conditional, as Crinis says in his Art of Dialectic, is one that is linked by the conjunction “since” and that consists of an antecedent proposition and a consequential proposition, for example, “Since it is day, it is light.” The conjunction declares both that the second follows from the first, and that the first is true. A conjunctive proposition is one that is conjoined by certain coordinating conjunctions, for example, “Both it is day, and it is light.” A disjunctive proposition is one that is disjoined by the disjunctive conjunction “either,” for example, “Either it is day, or it is night.” This conjunction declares that one or the other of the propositions is false. A causal proposition is one constructed by means of the conjunction “because,�
�� for example, “Because it is day, it is light.” For the first is, as it were, the cause of the second. The comparative proposition indicating the more is constructed with the conjunction that indicates “more” and with “than” placed between the propositions, for example, “It is more day than it is night.” The proposition that indicates the less is the opposite of the preceding one, for example, “It is less night than it is day.” Furthermore, among the propositions, some are opposed to one another with respect to truth and falsehood, where one is the negative of the other, for example, the propositions “It is day” and “It is not day.” A conditional proposition is true if the contradictory of its consequent conflicts with its antecedent, for example, “If it is day, it is light.” This is true; for the opposite of the conclusion, namely “It is not light,” conflicts with “It is day.” A conditional proposition is false if the contradictory of its consequent does not conflict with its antecedent, for example, “If it is day, Dion is walking.” For the proposition “Dion is not walking” does not conflict with “It is day.”
74 An affirmative conditional is true if it has a true antecedent, for example, “Since it is day, the sun is over the earth.” It is false if it has a false antecedent or an invalid consequent, for example, “Since it is night, Dion is walking,” if this is said when it is day.
75 A true causal proposition is one that reasons from a true antecedent to something that follows, but whose antecedent does not follow from the consequent, for example, “Because it is day, it is light”; for “It is light” follows from “It is day,” but “It is day” does not follow from “It is light.” A false causal proposition is one that either has a false antecedent, or reasons to a consequent that does not follow, or has an antecedent that follows from the consequent, for example, “Because it is night, Dion is walking.” A persuasive proposition is one that is conducive to assent, for example, “If someone gave birth to something, she is the mother of that thing.” This is false; for the hen is not the mother of an egg.
76 Furthermore, some propositions are possible, others impossible; and some are necessary, others nonnecessary. A proposition is possible if it admits of being true, provided that external factors do not oppose its being true, for example, “Diocles is alive.” A proposition is impossible if it does not admit of being true, for example, “The earth flies.” The necessary proposition is that which, besides being true, does not admit of being false, or does admit of being false, but external factors oppose its being false, for example, “Virtue is beneficial.” The nonnecessary is that which is both true and capable of being false if there are no external factors to prevent it from being false, for example, “Dion is walking.” A reasonable proposition is one that has more chances of being true than not, for example, “I will be alive tomorrow.”
And there are other differences among propositions, and transformations of them from true to false, and conversions—which we will describe in broad terms.
Dialectic or Industry (detail), by Veronese, 1575–1578.
An argument, as Crinis and his followers say, consists of a major premise, a minor premise, and a conclusion, for example, “If it is day, it is light. But it is day. Therefore it is light.” The major premise is “If it is day, it is light.” The minor premise is “But it is day.” The conclusion is “Therefore it is light.” A mode is a sort of outline for an argument, for example, “If the first, the second. But the first. Therefore the second.”
77 A mode-argument is a combination of the two, for example, “If Plato is alive, Plato breathes. But the first. Therefore the second.” The mode-argument was introduced so that in lengthy systems of arguments we need not repeat the minor premise, if it is long, and then the conclusion, but may draw the conclusion succinctly: “The first; therefore the second.”
Of arguments, some are invalid, others are valid. The invalid are those where the contradictory of the conclusion does not conflict with the conjunction of the premises, for example, “If it is day, it is light. But it is day. Therefore Dion is walking.”
78 Of valid arguments, some are called “valid,” after the entire class; others are called “syllogistic.” Syllogistic arguments are those that are either indemonstrable or reducible to the indemonstrables by one or more of the rules of reduction, for example, “If Dion is walking,
79 Furthermore, some arguments are true, others false. True arguments reach their conclusions by means of true premises, for example, “If virtue is beneficial, vice is harmful.
80,81 Certain arguments are also called indemonstrable because they require no demonstration. The lists of them vary from author to author. In Chrysippus there are five, by means of which every argument is constructed. These are used in valid arguments, syllogisms, and mode-arguments. The first indemonstrable is that in which the entire argument is constructed from a conditional and the antecedent of the conditional, with its consequent as conclusion, for example, “If the first, the second. But the first. Therefore the second.” The second indemonstrable is constructed from a conditional and the contradictory of the consequent, and concludes with the contradictory of the antecent, for example, “If it is day, it is light.
A truth follows from a truth, according to the Stoics, as “It is light” follows from “It is day.” And a falsehood follows from a falsehood, as “It is dark” follows from “It is night” if the latter is false. And a truth follows from a falsehood, as “The earth exists” follows from “The earth flies.” But a falsehood does not follow from a truth, for “The earth flies” does not follow from “The earth exists.”
82 There are also certain insoluble arguments: the Veiled Man, the Concealed Men, the Sorites, the Horned Men, and the Nobodies. The Veiled runs as follows <…> “It is not true that two are few but that three are not so likewise; and it is not true that two or three are few but four are not so; and so on up to ten. But two are few, therefore so are ten.” <…> The Nobody argument is a conditional argument that consists of an indefinite and a definite antecedent, with a minor premise and a conclusion, for example, “If somebody is here, it is not true that he is in Rhodes; but somebody is here, therefore it is not true that somebody is in Rhodes.”
83 Such, then, is the logic of the Stoics, by which they firmly establish that the wise man is always a dialectician. For all things are discerned by means of logical study, whether they belong to the domain of physics or, in turn, to that of ethics. (O
ne need not speak of its utility for logic.) Likewise with regard to the correct use of terms, and how laws have regulated actions, one would not know how to speak without dialectic. Moreover, of the two practices included under dialectical virtue, the one considers what each thing is, and the other what it is called. So much for their logic.
84 They divide the ethical part of philosophy into topics: impulse, things good and bad, passions, virtue, the goal and highest value, actions, duties, exhortations, and dissuasions. This is the subdivision adopted by Chrysippus, Archedemus, Zeno of Tarsus, Apollodorus, Diogenes, Antipater, and Posidonius. Zeno of Citium and Cleanthes, as might be expected of earlier philosophers, treated the subject less elaborately. But they did subdivide logic and physics.
85 They say that an animal’s first impulse is to preserve itself, because nature from the start makes the animal attached to itself, as Chrysippus states in the first book of his work On Goals, where he says that for every animal the first thing that belongs to it is its own constitution and its consciousness thereof. For it is not likely that nature would estrange the animal from itself, nor that she would create it and then neither estrange it from itself nor make it attached to itself. Accordingly, we are left to conclude that nature, in constituting the animal, made the animal attached to itself; for in this way it repels what is harmful and pursues what is appropriate.
86 What some people say, namely that the primary impulse of animals has pleasure as its object, the Stoics claim is false. For they say that pleasure, if it is actually felt, is a by-product that arises only after nature, by itself, has sought and found what is suitable to the animal’s constitution; it is in this way that animals frolic and plants bloom. They say that nature made no distinction between plants and animals, since she regulates the latter as well as the former without impulse and sensation; and even in us certain processes are plantlike. When, in the case of animals, impulse is added, by means of which they pursue what is appropriate for them, then for them what is natural is to be governed by impulse. And when reason, as a more perfect authority, has been bestowed on rational beings, then for them what is natural and proper is to be governed by reason. For reason, like a craftsman, overrides impulse.