In the preface to the first edition I expressed a strong opinion at variance with Mr. Grote's, that the so-called Epistles of Plato were spurious. His friend and editor, Professor Bain, thinks that I ought to give the reasons why I differ from so eminent an authority. Reserving the fuller discussion of the question for another place, I will shortly defend my opinion by the following arguments:-
(a) Because almost all epistles purporting to be of the classical age of Greek literature are forgeries1. Of all documents this class are the least likely to be preserved and the most likely to be invented. The ancient world swarmed with them; the great libraries stimulated the demand for them; and at a time when there was no regular publication of books, they easily crept into the world.
(b) When one epistle out of a number is spurious, the remainder of the series cannot be admitted to be genuine, unless there be some independent ground for thinking them so : when all but one are spurious, overwhelming evidence is required of the genuineness of the one: when they are all similar in style or motive, like witnesses who agree in the same tale, they stand or fall together. But no one, not even Mr. Grote, would maintain that all the Epistles of Plato are genuine, and very few critics think that more than one of them is so. And they are clearly all written from the same motive, whether serious or only literary. Nor is there an example in Greek antiquity of a series of Epistles, continuous and yet coinciding with a succession of events extending over a great number of years.
The external probability therefore against them is enormous, and the internal probability is not less: for they are trivial and unmeaning, devoid of delicacy and subtlety, wanting in a single fine expression. And even if this be matter of dispute, there can be no dispute that there are found in them many plagiarisms, inappropriately borrowed, which is a common note of forgery. They imitate Plato, who never imitates either himself or any one else; reminiscences of the Republic and the Laws are continually recurring in them; they are too like him and also too unlike him, to be genuine. They are full of egotism, self-assertion, affectation, faults which of all writers Plato was most careful to avoid, and into which he was least likely to fall. They abound in obscurities, irrelevancies, solecisms, pleonasms, inconsistencies, awkwardnesses of construction, wrong uses of words. They also contain historical blunders, such as the statement respecting Hipparinus and Nysaeus, the nephews of Dion (328 A), who are said to 'have been well inclined to philosophy, and well able to dispose the mind of their brother Dionysius in the same course, at a time when they could not have been more than six or seven years of age - also foolish allusions, such as the comparison of the Athenian empire to the empire of Darius (332 A, B), which show a spirit very different from that of Plato; and mistakes of fact, as e.g. about the Thirty Tyrants (p. 324 C), whom the writer of the letters seems to have confused with certain inferior magistrates, making them in all fifty-one. These palpable errors and absurdities are absolutely irreconcileable with their genuineness. And as they appear to have a common parentage, the more they are studied, the more they will be found to furnish evidence against themselves. The Seventh, which is thought to be the most important of these Epistles, has affinities with the Third and the Eighth, and is quite as impossible and inconsistent as the rest. It is therefore involved in the same condemnation. - The final conclusion is that neither the Seventh nor any other of them, when carefully analyzed, can be imagined to have proceeded from the hand or mind of Plato. The other testimonies to the voyages of Plato to Sicily and the court of Dionysius are all of them later by several centuries than the events to which they refer. No extant writer mentions them older than Cicero and Cornelius Nepos. It does not seem impossible that so attractive a theme as the meeting of a philosopher and a tyrant, once imagined by the genius of a Sophist, may have passed into a romance which became famous in Hellas and the world. It may have created one of the mists of history, like the Trojan war or the legend of Arthur, which we are unable to penetrate. In the age of Cicero, and still more in that of Diogenes Laertius and Appuleius, many other legends had gathered around the personality of Plato, - more voyages, more journeys to visit tyrants and Pythagorean philosophers. But if, as we agree with Karsten in supposing, they are the forgery of some rhetorician or sophist, we cannot agree with him in also supposing that they are of any historical value, the rather as there is no early independent testimony by which they are supported or with which they can be compared.