But the higher flights of Plato about the science of dialectic, or the unity of virtue, or a person who is above the law, would be unintelligible to him.
(c) The argument from imitation assumes a different character when the supposed imitations are associated with other passages having the impress of original genius.

The strength of the argument from undesigned coincidences of style is much increased when they are found side by side with thoughts and expressions which can only have come from a great original writer.

The great excellence, not only of the whole, but even of the parts of writings, is a strong proof of their genuineness--for although the great writer may fall below, the forger or imitator cannot rise much above himself.

Whether we can attribute the worst parts of a work to a forger and the best to a great writer,--as for example, in the case of some of Shakespeare's plays,--depends upon the probability that they have been interpolated, or have been the joint work of two writers; and this can only be established either by express evidence or by a comparison of other writings of the same class.

If the interpolation or double authorship of Greek writings in the time of Plato could be shown to be common, then a question, perhaps insoluble, would arise, not whether the whole, but whether parts of the Platonic dialogues are genuine, and, if parts only, which parts.