never attributes
any passage found in the extant dialogues to any one but Plato. And
lastly, we may remark that one or two great writings, such as the
Parmenides and the Politicus, which are wholly devoid of Aristotelian
(1) credentials may be fairly attributed to Plato, on the ground of (2)
length, (3) excellence, and (4) accordance with the general spirit
of his writings. Indeed the greater part of the evidence for the
genuineness of ancient Greek authors may be summed up under two heads
only: (1) excellence; and (2) uniformity of tradition--a kind of
evidence, which though in many cases sufficient, is of inferior value.

Proceeding upon these principles we appear to arrive at the conclusion
that nineteen-twentieths of all the writings which have ever been
ascribed to Plato, are undoubtedly genuine. There is another portion of
them, including the Epistles, the Epinomis, the dialogues rejected by
the ancients themselves, namely, the Axiochus, De justo, De virtute,
Demodocus, Sisyphus, Eryxias, which on grounds, both of internal and
external evidence, we are able with equal certainty to reject. But there
still remains a small portion of which we are unable to affirm either
that they are genuine or spurious. They may have been written in youth,
or possibly like the works of some painters, may be partly or wholly
the compositions of pupils; or they may have been the writings of some
contemporary transferred by accident to the more celebrated name of
Plato, or of some Platonist in the next generation who aspired to
imitate his master. Not that on grounds either of language or philosophy
we should lightly reject them. Some difference of style, or inferiority
of execution, or inconsistency of thought, can hardly be considered
decisive of their spurious character. For who always does justice to
himself, or who writes with equal care at all times? Certainly not
Plato, who exhibits the greatest differences in dramatic power, in the
formation of sentences, and in the use of words, if his earlier writings
are compared with his later ones, say the Protagoras or Phaedrus with
the Laws. Or who can be expected to think in the same manner during
a period of authorship extending over above fifty years, in an age
of great intellectual activity, as well as of political and literary
transition? Certainly not Plato, whose earlier writings are separated
from his later ones by as wide an interval of philosophical speculation
as that which s