pages,' he says, 'will, I fear, detract somewhat from its value,
but I have written my work not to be the exploit of a passing hour
but as the possession of all time.' (18) Polybius follows with
words almost entirely similar. If, he says, we banish from history
the consideration of causes, methods and motives ([Greek text which
cannot be reproduced]), and refuse to consider how far the result
of anything is its rational consequent, what is left is a mere
[Greek text which cannot be reproduced], not a [Greek text which
cannot be reproduced], an oratorical essay which may give pleasure
for the moment, but which is entirely without any scientific value
for the explanation of the future. Elsewhere he says that 'history
robbed of the exposition of its causes and laws is a profitless
thing, though it may allure a fool.' And all through his history
the same point is put forward and exemplified in every fashion.

So far for the conception of history. Now for the groundwork. As
regards the character of the phenomena to be selected by the
scientific investigator, Aristotle had laid down the general
formula that nature should be studied in her normal manifestations.
Polybius, true to his character of applying explicitly the
principles implicit in the work of others, follows out the doctrine
of Aristotle, and lays particular stress on the rational and
undisturbed character of the development of the Roman constitution
as affording special facilities for the discovery of the laws of
its progress. Political revolutions result from causes either
external or internal. The former are mere disturbing forces which
lie outside the sphere of scientific calculation. It is the latter
which are important for the establishing of principles and the
elucidation of the sequences of rational evolution.