makes use of any preface, he need not divide it as our orators do,
into three parts, but confine it to two, leaving out his address to
the benevolence of his readers, and only soliciting their attention
and complacency: their attention he may be assured of, if he can
convince them that he is about to speak of things great, or
necessary, or interesting, or useful; nor need he fear their want of
complacency, if he clearly explains to them the causes of things,
and gives them the heads of what he intends to treat of.

Such are the exordiums which our best historians have made use of.
Herodotus tells us, "he wrote his history, lest in process of time
the memory should be lost of those things which in themselves were
great and wonderful, which showed forth the victories of Greece, and
the slaughter of the barbarians;" and Thucydides sets out with
saying, "he thought that war most worthy to be recorded, as greater
than any which had before happened; and that, moreover, some of the
greatest misfortunes had accompanied it." The exordium, in short,
may be lengthened or contracted according to the subject matter, and
the transition from thence to the narration easy and natural. The
body of the history is only a long narrative, and as such it must go
on with a soft and even motion, alike in every part, so that nothing
should stand too forward, or retreat too far behind. Above all, the
style should be clear and perspicuous, which can only arise, as I
before observed, from a harmony in the composition: one thing
perfected, the next which succeeds should be coherent with it; knit
together, as it were, by one common chain, which must never be
broken: they must not be so many separate and distinct narratives,
but each so closely united to what follows, as to appear one
continued series.