But it should be recognised that a forger of letters
purporting to belong to Plato's old age would
naturally imitate the later dialogues — that is, if
we suppose him to have known the chronology of
the dialogues, a knowledge we have no right to
assume him not to have possessed. Nevertheless,
the establishment of this lexical affinity is by no
means useless. For if we had not been able to
establish it we must have rejected the letters out
of hand : and an obvious preliminary to establish-
ing Platonic authorship is to establish Platonic
diction. It is not too much to say that lexical
affinity, to the later dialogues in particular,
affords us a presumption in favour of authenticity,
a presumption which must be confirmed by other
considerations : and on this principle the remarks
on language in the following pages must be
interpreted. Proof of authenticity, if proof be
possible, must be sought by a detailed examina-
tion of each Epistle : and in this examination, I
may now conveniently state, the presumption
which we have formed in favour of iii, vii and viii
will be confirmed, and these three letters I believe



GENERAL INTRODUCTION 35

to be Platonic beyond all reasonable doubt : iv
and xiii show evidence of authenticity only next
to these : ix, x and xi must be left doubtful,
chiefly because of their brevity : while i, ii, v, vi,
xii are unquestionably spurious.
