lines, the average pressure for any month or season over large areas. The daily weather charts for more confined regions indicate the presence of a cyclonic or anticyclonic system by means of lines, which connect all places having the same barometric pressure at the same time. It is to be noted that isobaric lines are the intersections of inclined isobaric surfaces with the surface of the earth.
ISOCLINIC LINES (Gr. ἴσος, equal, and κλίνειν, to bend), lines connecting those parts of the earth’s surface where the magnetic inclination is the same in amount. (See Magnetism, Terrestrial.)
ISOCRATES (436-338 B.C.), Attic orator, was the son of Theodorus, an Athenian citizen of the deme of Erchia—the same in which, about 431 B.C., Xenophon was born—who was sufficiently wealthy to have served the state as choregus. The fact that he possessed slaves skilled in the trade of flute-making perhaps lends point to a passage in which his son is mentioned by the comic poet Strattis. Several popular “sophists” are named as teachers of the young Isocrates. Like other sons of prosperous parents, he may have been trained in such grammatical subtleties as were taught by Protagoras or Prodicus, and initiated by Theramenes into the florid rhetoric of Gorgias, with whom at a later time (about 390 B.C.) he was in personal intercourse. He tells us that his father had been careful to provide for him the best education which Athens could afford. A fact of greater interest is disclosed by Plato’s Phaedrus (278 E). “Isocrates is still young, Phaedrus,” says the Socrates of that dialogue, “but I do not mind telling you what I prophesy of him.... It would not surprise me if, as years go on, he should make all his predecessors seem like children in the kind of oratory to which he is now addressing himself, or if—supposing this should not content him—some divine impulse should lead him to greater things. My dear Phaedrus, a certain philosophy is inborn in him.” This conversation is dramatically supposed to take place about 410 B.C. It is unnecessary to discuss here the date at which the Phaedrus was actually composed. From the passage just cited it is at least clear that there had been a time—while Isocrates could still be called “young”—at which Plato had formed a high estimate of his powers.
Isocrates took no active part in the public life of Athens; he was not fitted, as he tells us, for the contests of the popular assembly or of the law-courts. He lacked strength of voice—a fatal defect in the ecclesia, when an audience of many thousands was to be addressed in the open air; he was also deficient in “boldness.” He was, in short, the physical opposite of the successful Athenian demagogue in the generation after that of Pericles; by temperament as well as taste he was more in sympathy with the sedate decorum of an older school. Two ancient biographers have, however, preserved a story which, if true, would show that this lack of voice and nerve did not involve any want of moral courage. During the rule of the Thirty Tyrants, Critias denounced Theramenes, who sprang for safety to the sacred hearth of the council chamber. Isocrates alone, it is said, dared at that moment to plead for the life of his friend. Whatever may be the worth of the story, it would scarcely have connected itself with the name of a man to whose traditional character it was repugnant. While the Thirty were still in power, Isocrates withdrew from Athens to Chios. He has mentioned that, in the course of the Peloponnesian War—doubtless in the troubles which attended on its close—he lost the whole of that private fortune which had enabled his father to serve the state, and that he then adopted the profession of a teacher. The proscription of the “art of words” by the Thirty would thus have given him a special motive for withdrawing from Athens. He returned thither, apparently, either soon before or soon after the restoration of the democracy in 403 B.C.
For ten years from this date he was occupied—at least occasionally—as a writer of speeches for the Athenian law-courts. Six of these speeches are extant. The earliest (Or. xxi.) may be referred to 403 B.C.; the latest (Or. xix.) to 394-393 B.C. This was a department of his own work which Isocrates afterwards preferred to ignore. Nowhere, indeed, does he say that he had not written forensic speeches. But he frequently uses a tone from which that inference might be drawn. He loves to contrast such petty concerns as engage the forensic writer with those larger and nobler themes which are treated by the politician. This helps to explain how it could be asserted—by his adopted son, Aphareus—that he had written nothing for the law-courts. Whether the assertion was due to false shame or merely to ignorance, Dionysius of Halicarnassus decisively disposes of it. Aristotle had, indeed, he says, exaggerated the number of forensic speeches written by Isocrates; but some of those which bore his name were unquestionably genuine, as was attested by one of the orator’s own pupils, Cephisodorus. The real vocation of Isocrates was discovered from the moment that he devoted himself to the work of teaching and writing. The instruction which Isocrates undertook to impart was based on rhetorical composition, but it was by no means merely rhetorical. That “inborn philosophy,” of which Plato recognized the germ, still shows itself. In many of his works—notably in the Panegyricus—we see a really remarkable power of grasping a complex subject, of articulating it distinctly, of treating it, not merely with effect but luminously, at once in its widest bearings and in its most intricate details. Young men could learn more from Isocrates than the graces of style; nor would his success have been what it was if his skill had been confined to the art of expression.
It was about 392 B.C.—when he was forty-four—that he opened his school at Athens near the Lyceum. In 339 B.C. he describes himself as revising the Panathenaicus with some of his pupils; he was then ninety-seven. The celebrity enjoyed by the school of Isocrates is strikingly attested by ancient writers. Cicero describes it as that school in which the eloquence of all Greece was trained and perfected: its disciples were “brilliant in pageant or in battle,”}} foremost among the accomplished writers or powerful debaters of their time. The phrase of Cicero is neither vague nor exaggerated. Among the literary pupils of Isocrates might be named the historians Ephorus and Theopompus, the Attic archaelogist Androtion, and Isocrates of Apollonia, who succeeded his master in the school. Among the practical orators we have, in the forensic kind, Isaeus; in the political, Leodamas of Acharnae, Lycurgus and Hypereides. Hermippus of Smyrna (mentioned by Athenaeus) wrote a monograph on the “Disciples of Isocrates.” And scanty as are now the sources for such a catalogue, a modern scholar has still been able to recover forty-one names. At the time when the school of Isocrates was in the zenith of its fame it drew disciples, not only from the shores and islands of the Aegean, but from the cities of Sicily and the distant colonies of the Euxine. As became the image of its master’s spirit, it was truly Panhellenic. When Mausolus, prince of Caria, died in 351 B.C., his widow Artemisia instituted a contest of panegyrical eloquence in honour of his memory. Among all the competitors there was not one—if tradition may be trusted—who had not been the pupil of Isocrates.
Meanwhile the teacher who had won this great reputation had also been active as a public writer. The most interesting and most characteristic works of Isocrates are those in which he deals with the public questions of his own day. The influence which he thus exercised throughout Hellas might be compared to that of an earnest political essayist gifted with a popular and attractive style. And Isocrates had a dominant idea which gained strength with his years, until its realization had become, we might say, the main purpose of his life. This idea was
- Ἀταλάντη, fr. 1, Meineke, Poëtarum comicorum Graecorum frag. (1855), p. 292.
- [Plut.] Vita Isocr., and the anonymous biographer. Dionysius does not mention the story, though he makes Isocrates a pupil of Theramenes.
- Some would refer the sojourn of Isocrates at Chios to the years 398-395 B.C., others to 393-388 B.C. The reasons which support the view given in the text will be found in Jebb’s Attic Orators, vol. ii. (1893), p. 6, note 2.
- Partim in pompa, partim in acie illustres (De orat. ii. 24).
- P. Sanneg, De schola Isocratea (Halle, 1867).