Aristophanes 
The Clouds [EPUB ebook] 

The satire in this, one of the best known of all Aristophanes’ comedies, is directed against the new schools of philosophy, or perhaps we should rather say dialectic, which had lately been introduced, mostly from abroad, at Athens. The doctrines held up to ridicule are those of the 'Sophists’—such men as Thrasymachus from Chalcedon in Bithynia, Gorgias from Leontini in Sicily, Protagoras from Abdera in Thrace, and other foreign scholars and rhetoricians who had flocked to Athens as the intellectual centre of the Hellenic world.—From the introduction to ‘The Clouds’ by Aristophanes.