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. Hebrew prophecies and Homeric
poems and Laws of Manu may have grown together in early times, but there
is no reason to think that any of the dialogues of Plato is the result
of a similar process of accumulation. It is therefore rash to say
with Oncken (Die Staatslehre des Aristoteles) that the form in which
Aristotle knew the Laws of Plato must have been different from that in
which they have come down to us.

It must be admitted that these principles are difficult of application.
Yet a criticism may be worth making which rests only on probabilities
or impressions. Great disputes will arise about the merits of different
passages, about what is truly characteristic and original or trivial
and borrowed. Many have thought the Laws to be one of the greatest of
Platonic writings, while in the judgment of Mr. Grote they hardly rise
above the level of the forged epistles. The manner in which a writer
would or would not have written at a particular time of life must be
acknowledged to be a matter of conjecture. But enough has been said to
show that similarities of a certain kind, whether criticism is able to
detect them or not, may be such as must be attributed to an original
writer, and not to a mere imitator.

(d) Applying these principles