Sibyl of History burned her volumes. Besides, as Gibbon pointed
out, 'a Montesquieu will detect in the most insignificant fact
relations which the vulgar overlook.'

Nor can the scientific investigator of history isolate the
particular elements, which he desires to examine, from disturbing
and extraneous causes, as the experimental chemist can do (though
sometimes, as in the case of lunatic asylums and prisons, he is
enabled to observe phenomena in a certain degree of isolation). So
he is compelled either to use the deductive mode of arguing from
general laws or to employ the method of abstraction, which gives a
fictitious isolation to phenomena never so isolated in actual
existence. And this is exactly what Polybius has done as well as
Thucydides. For, as has been well remarked, there is in the works
of these two writers a certain plastic unity of type and motive;
whatever they write is penetrated through and through with a
specific quality, a singleness and concentration of purpose, which
we may contrast with the more comprehensive width as manifested not
merely in the modern mind, but also in Herodotus. Thucydides,
regarding society as influenced entirely by political motives, took
no account of forces of a different nature, and consequently his
results, like those of most modern political economists, have to be
modified largely (20) before they come to correspond with what we
know was the actual state of fact. Similarly, Polybius will deal
only with those forces which tended to bring the civilised world
under the dominion of Rome (ix. 1), and in the Thucydidean spirit
points out the want of picturesqueness and romance in his pages
which is the result of the abstract method ([Greek text which
cannot be reproduced]) being careful also to tell us that his
rejection of all other forces is essentially deliberate and the