The Complete Aristotle (eng.)

this method formerly; not many do so now.
By ‘free-running’ style I mean the kind that has no natural
stopping-places, and comes to a stop only because there is no more
to say of that subject. This style is unsatisfying just because it
goes on indefinitely-one always likes to sight a stopping-place in
front of one: it is only at the goal that men in a race faint and
collapse; while they see the end of the course before them, they
can keep on going. Such, then, is the free-running kind of style;
the compact is that which is in periods. By a period I mean a
portion of speech that has in itself a beginning and an end, being
at the same time not too big to be taken in at a glance. Language
of this kind is satisfying and easy to follow. It is satisfying,
because it is just the reverse of indefinite; and moreover, the
hearer always feels that he is grasping something and has reached
some definite conclusion; whereas it is unsatisfactory to see
nothing in front of you and get nowhere. It is easy to follow,
because it can easily be remembered; and this because language when
in periodic form can be numbered, and number is the easiest of all
things to remember. That is why verse, which is measured, is always
more easily remembered than prose, which is not: the measures of
verse can be numbered. The period must, further, not be completed
until the sense is complete: it must not be capable of breaking off
abruptly, as may happen with the following iambic lines of
Sophocles—
Calydon’s soil is this; of Pelops’ land
(The smiling plains face us across the strait.)
    By a wrong division of the words the hearer may take the meaning
to be the reverse of what it is: for instance, in the passage
quoted, one might imagine that Calydon is in the Peloponnesus.
    A Period may be either divided into several members or simple.
The period of several members is a portion of speech (1) complete
in itself, (2) divided into parts, and (3) easily delivered at a
single breath-as a whole, that is; not by fresh breath being taken
at the division. A member is one of the two parts of such a period.
By a ‘simple’ period, I mean that which has only one member. The
members, and the whole periods, should be neither curt nor long. A
member which is too short often makes the listener stumble; he is
still expecting the rhythm to go on to the limit his mind has fixed
for it; and if meanwhile he is pulled back by the speaker’s
stopping, the shock is bound to make him, so to speak, stumble. If,
on the other hand, you go on too long, you make him feel left
behind, just as people who when walking pass beyond the boundary
before turning back leave their companions behind So too if a
period is too long you turn it into a speech, or something like a
dithyrambic prelude. The result is much like the preludes that
Democritus of Chios jeered at Melanippides for writing instead of
antistrophic stanzas—
He that sets traps for another man’s feet
Is like to fall into them first;
And long-winded preludes do harm to us all,
But the preluder catches it worst.
    Which applies likewise to long-membered orators. Periods whose
members are altogether too short are not periods at all; and the
result is to bring the hearer down with a crash.
    The periodic style which is divided into members is of two
kinds. It is either simply divided, as in ‘I have often wondered at
the conveners of national gatherings and the founders of athletic
contests’; or it is antithetical, where, in each of the two
members, one of one pair of opposites is put along with one of
another pair, or the same word is used to bracket two opposites, as
‘They aided both parties-not only those who stayed behind but those
who accompanied them: for the latter they acquired new territory
larger than that at home, and to the former they left territory at
home that was large enough’. Here the contrasted words are ‘staying
behind’ and ‘accompanying’, ‘enough’ and ‘larger’. So in the
example, ‘Both to those who want to get property and to those who
desire to enjoy it’ where ‘enjoyment’ is contrasted with ‘getting’.
Again, ‘it often happens in such enterprises that the wise men fail
and the fools succeed’; ‘they were awarded the prize of valour
immediately, and won the command of the sea not long afterwards’;
‘to sail through the mainland and march through the sea, by
bridging the Hellespont and cutting through Athos’; ‘nature gave
them their country and law took