1
Plato: Logic and Political Reality
Logic has been described as an instrument of thought to guide man in an orderly way, with ease and without error, inthe construction of science. It is reasonable to suppose, then, that the art of thinking should not at its beginning have benefited by the perfection of its instruments. And this is indeed the case. If we agreeâand it is commonly agreedâto fix the beginning of systematic philosophic speculation in the Western world at the seventh century b.c. in Greece, we then find that for two centuries the human mind grappled with the most difficult matters without the aid of adequate instruments of thought. And yet, because one cannot disassociate the object of science from the way in which that object is thought about, it was natural that the early philosophers should have touched to some extent upon problems of logic. As Aristotle remarks, in speaking of the first principles of thought, âsome natural philosophers indeed [have treated of these matters] and their procedure was intelligible enough; for they thought that they were alone inquiring about the whole of nature and about being.â1 But since, as Aristotle points out, the rules of thought are applicable in every science (âand all men use themâ), âno one who is conducting a special inquiry tries to say anything about their truth or falsityâneither the geometrician nor the arithmeticianâ2 Indeed, the students of particular sciences, he goes on to observe, ââshould know these things (the rules of logic) already when they come to a special study, and not be inquiring into them while they are listening to lectures on [their special study].â3
Now Greek philosophy took its beginnings with the special study of the physical universe. We need merely advert here to the fact that, because of the failure to make prior investigation into the nature and conditions of human knowledge, this opening period of Greek philosophy (known as the Cosmological Period), extending from the seventh to fifth centuries, ended in a condition of complete intellectual paralysis. The impasse reached in the fifth century is perhaps best reflected in the conflicting theories of two of the greatest of the early thinkers, Heraclitus and Parmenides. It was the teaching of Heraclitus that the only reality is change; there is no underlying substratum that may be said to undergo change, and therefore Heraclitus was saying that science is impossible, for science ought to be necessary and certain, at least in part. Parmenides of Elea had succeeded in transcending the world of physical bodies and even that of mathematical forms, and had attained the notion of being as such. But since, according to Parmenides, that which is, is, and that which is not, is not, there is only one science possible: the science of being. The distinction of things is an illusion because the only difference between two beings must necessarily be non-being, and non- being is not; hence all things are one, without distinction and without change. The philosophy of Parmenides found its most brilliant apologist in Zeno, and the arguments of Zeno appeared to his opponents to be unanswerable. The paradoxes of Zeno became famous; they were designed to show the impossibility of change and plurality. He argued, for example, that motion cannot possibly begin because a body in motion cannot arrive at another place until it has passed half the distance between its point of departure and its goal; but the number of intermediate points is not just one but is infinite; for half the space must be transversed, and half of that and half of that, and so on ad infinitum. Since an infinite space cannot be traversed in a finite time, motion is obviously an illusion of the senses.
In discussing the notions of these men, who were his predecessors, Aristotle adverts to the logical problems (among others) inherent in their dilemmas. Heraclitus was in effect saying that it is possible for the same thing to be and not to be at the same time and in the same respect; though, as Aristotle shrewdly observes, âwhat a man says, he does not necessarily believe.â4 Nonetheless, this was what Heraclitus was saying; and indeed, âthis belief . . . blossomed in the most extreme (view) . . . such as was held by Cratylus, who finally did not think it right to say anything, but only moved his finger, and criticized Heraclitus for saying that it is impossible to step twice into the same river; for he thought one could not do it even once.â5 Parmenides, on the other hand, had maintained that all things are one. Fastening on that which is one in definition, he held that one is used in this single sense only and concluded that âbeingâ has the same meaning, of whatever it is predicated, and that it means both just what is and what is one.6
The Sophists
The difficulties attendant upon the theories of the Greek physicists were indeed insurmountable until such time as the principles of thought should themselves be established. The result was an impasse and a crisis in Greek philosophy. Despairing of reaching truth in the field of physics, men turned toward what appeared to them to be the more easily accessible field of human behavior.7 The new emphasis on humanistic studies was carried out, toward the middle of the fifth century, by the itinerant teachers in Athens, known as sophists.8 The new humanism of the sophists did not, however, entirely set aside the ways of thinking followed by the older philosophers of nature. The Greeks of the fifth century had found in the âfluxâ of Heraclitus the analogue of changing custom and convention in human affairs; and their inquiry was addressed, similarly to that of the early physicists, to the possible existence of some underlying principle of permanence in human life. At the middle of the fifth century, Protagoras of Abdera, taking account of the teachings of Heraclitus and Parmenides, drew the skeptical inference from their doctrine: If, as Heraclitus had maintained, all things are in flux, or if, as Parmenides had held, the multiplicity of things is the subject matter for opinion but not knowledge, then âMan is the measure of all things, of what is, that it is, and what is not that it is not.â In a similar way, the sophist Gorgias of Leontini, called the Nihilist, deriving inspiration from Parmenides, maintained that the destruction of the popular belief in the existence of the multiplicity of things led not to the existence of the one (as Parmenides had taught) but to the proposition that nothing must be, since nothing is: That if anything were, it could not be known; and that if anything could be known it could not be communicated. Gorgias in fact availed himself of the arguments which Zeno had used, but to prove, contrary to Zenoâs demonstration, that it is just non-being that is and is one. Thus where Protagoras had held that truth is relative to the individual and that all opinions are equally true, Gorgias held that because nothing is, all opinions are equally false. Those among the sophists who were inclined to suppose that there is some underlying principle in human affairsâsomething ânaturalâ to all menâwere no more successful in escaping the skepticism and subjectivism that were the legacy of earlier physicists. The sophist Callicles, as Plato presents his position in the dialogue called Gorgias, finds that âto suffer (rather than to do) injustice is the greater disgrace because the greater evil; but conventionally to do evil is the more disgraceful; . . . whereas nature herself . . . in many ways (shows), among men as well as among animals, and indeed among whole cities and races that justice consists in the superior ruling over and having more than the inferior.â9 It follows then, that the conventional âjusticeâ of a state represents either (1) an attempt to thwart nature by setting up a barrier for the protection of the multitude of weaklings, or (2) conventional justice is simply the conventional expression of the natural strength of the strong. This position is defended at some length by the sophist Thrasymachus, whose views are reported for us by Plato in the Republic:
Each government has its laws framed to suit its own interests; a democracy making democratical laws; an autocrat despotic laws; and so on. Now by this procedure these governments have pronounced that what is for the interest of themselves is just for their subjects; and whoever deviates from this, is chastised by them as guilty of illegality and injustice. Therefore, my good sir, my meaning is, that in all cities the same thing, namely, the interest of the established government, is just. And superior strength, I presume, is to be found on the side of government. So that the conclusion of right reasoning is that the same thing, namely, the interest of the stronger, is everywhere just.10
Socrates and Plato
The sophists had indeed effected a transition from philosophy as cosmology to philosophy as concerning itself with man as a thinking subject; but the character of their pursuit was hardly suited to the task of finding a scientific basis for a theory of knowledge and a science of morals. It was, however, as a catalytic that they served to precipitate a genuine inquiry into the conditions of knowledge, and thus negatively to advance philosophy to the point where the problems left by Parmenides and Heraclitus could be solved. The man who was to rescue Greek philosophy from its parlous state was Socrates (b. 469 b.c.). Although a devoted student of one of the more distinguished sophists, Prodicus, Socrates dedicated his life to eradicating the deadly disease of sophistry from Greek life. Socrates committed none of his doctrine to writing; he led, in fact, very much the same sort of life as his opponents, the sophists, spending his time in discussion with the young men of Athens. Our knowledge of his teaching comes from the accounts of Xenophon, one of his students, and above all from Plato, his great disciple. It is from Aristotle, however, that we have the most valuable information on the teaching of Socrates, and in Book XIII of his Metaphysics he tells us that Socrates was the first of the Greek thinkers to raise the problem of universal definition. âFor of the physicists,â Aristotle writes, âDemocritus only touched on the subject to a small extent. . . .â11 âBut it was natural,â continues Aristotle, âthat Socrates should be seeking the essence, for he was seeking to syllogize, and âwhat a thing isâ is the starting point of syllogisms; . . . for two things may be fairly ascribed to Socratesâinductive argument and universal definition, both of which are concerned with the starting point of science.â12 The method which Socrates employed, called âmaieutic,â the art of intellectual midwifery, sought to aid the intellect in bringing forth its proper object by seeking the essences of things and expressing them in definitions. Philosophy had now advanced beyond the stage where it sought some one universal natureâwater, air, fire, numbers, or even absolute beingâas the ultimate substance of everything. Socrates had, on the contrary, engaged it in the task of determining and defining the essence of each thing by genus and difference, by a concept proper to itself alone. If we wish to see the Socratic method in operation, we have only to study the masterly use of it in the great dialogues of Plato. Consider, for example, Platoâs reply to the very powerful objections made by the sophists against the possibility of the existence of scientific truth in moral matters: The sophists plausibly maintained that if there were anything universally right in morals it would be everywhere the same; but there is obviously nothing so right in human affairs that it obtains force everywhere. In Carthage the sacrifice of human beings was considered a holy and lawful thing, while in Athens it was condemned by law. âWhat else can law be,â the sophist asks, âif not (merely) the things established by law?â To this question Plato replies, through the mouth of Socrates:
If I asked instead what is gold, you would not inquire, what kind of gold. For gold cannot differ from gold, so far as it is gold. Nor can law differ from law, in so far as they really are law. Law, therefore, cannot be merely the sum of existing legal rules, for some decrees are good and some evil, but law cannot be evil. Hence all decrees cannot be law, but those only that are good and consonant to law in its true sense. Law, then, is the discovery of a good that exists, it can be discovered only by those who are wise, and such above all are statesmen and kings, whose writings relating to the state men generally call laws. But it is the decree only of the good and the wise that we may rightly call laws, and one that is not right we shall no longer call lawful; it becomes âunlawful.â13
It is ...