Update (2013 December 16): see below for an informative comment by Professor Harold Tarrant.
We have just posted to www.protrepticus.info a short essay on the title and length of Aristotle's Protrepticus, based on the evidence of the ancient lists of titles of Aristotle's works, and similar titles by other authors. Let us know what you think!
From Harold Tarrant:
Just looked at your brief
account of the Protr. length, and I wondered whether this investigation
might go on to tell us a little more. One consideration is that a
‘Protreptic’
is going to be addressed to somebody not yet committed to philosophy,
which means that a long work of philosophy would be unlikely to retain
attention, unless other factors (literary presentation, humor etc.) were
involved. Something relatively succinct would
have been most effective. One-book Platonic dialogues of an obviously
exoteric kind, range from about 1600 words (for the
Clitophon, significant?) to around 10000, with the big exception being
Gorgias, at over 26000, and there is (as Dodds points out) a
papyrus list of philosophic books (associated with the book trade) that
makes reference to
Against Callicles in 3 books, which may be the
Gorgias. Average length of books of
Republic = 8880, Laws 8582 words, and a three-book
Gorgias would have come in at 8772 (my count separates out hiatus
and will vary slightly from others). I reckon that a book intended to
circulate widely in one book would originally have been written for some
kind of
standard length papyrus-roll, coming in at 10000 words or under. I
doubt that Protr. would have been much longer. A quick count of my files
of the relevant material in Iambl.
Protr. 5-12 suggests that we may already have about 5000 words of
Aristotle, so I'm guessing that only another 3500 would have been
needed to bring it up to the length of (e.g.)
Charmides or a book of the
Republic—some of which can be supplied from DCMS. I reckon that if
he had written more than 12000 words it would be recorded as two or more
books, since 2-3 books are quite common in the lists. It would be
gratifying if we did in fact have the bulk of
Protr. already!