The Metamorphoses of Ovid, Books I-VII

The story of the Metamorphosis of Io has been already enlarged upon in the Explanation of the preceding Fable. It may, however, not be irrelevant to observe, that myths, or mythological stories or fables, are frequently based upon some true history, corrupted by tradition in lapse of time. The poets, too, giving loose to their fancy in their love of the marvellous, have still further disfigured the original story; so that it is in most instances extremely difficult to trace back the facts to their primitive simplicity, by a satisfactory explanation of each circumstance attending them, either upon a philosophical, or an historical principle of solution.