is to annihilate the possibility of history: for just as
scientific and chemical experiments would be either impossible or

useless if exposed to the chance of continued interference on the
part of some foreign body, so the laws and principles which govern

history, the causes of phenomena, the evolution of progress, the
whole science, in a word, of man's dealings with his own race and

with nature, will remain a sealed book to him who admits the
possibility of extra-natural interference.

The stories of miracles, then, are to be rejected on A PRIORI
rational grounds, but in the case of events which we know to have

happened the scientifichistorian will not rest till he has
discovered their natural causes which, for instance, in the case of

the wonderful rise of the Roman Empire - the most marvellous thing,
Polybius says, which God ever brought about (16) - are to be found

in the excellence of their constitution ([Greek text which cannot
be reproduced]), the wisdom of their advisers, their splendid

military arrangements, and their superstition ([Greek text which
cannot be reproduced]). For while Polybius regarded the revealed

religion as, of course, objectivereality of truth, (17) he laid
great stress on its moral subjective influence, going, in one

passage on the subject, even so far as almost to excuse the
introduction of the supernatural in very small quantities into

history on account of the extremely good effect it would have on
pious people.

But perhaps there is no passage in the whole of ancient and modern
history which breathes such a manly and splendid spirit of

rationalism as one preserved to us in the Vatican - strange
resting-place for it! - in which he treats of the terrible decay of

population which had fallen on his native land in his own day, and
which by the general orthodox public was regarded as a special

judgment of God sending childlessness on women as a punishment for
the sins of the people. For it was a disaster quite without

parallel in the history of the land, and entirely unforeseen by any
of its political-economy writers who, on the contrary, were always

anticipating that danger would arise from an excess of population
overrunning its means of subsistence, and becoming unmanageable

through its size. Polybius, however, will have nothing to do with
either priest or worker of miracles in this matter. He will not

even seek that 'sacred Heart of Greece,' Delphi, Apollo's shrine,
whose inspiration even Thucydides admitted and before whose wisdom

Socrates bowed. How foolish, he says, were the man who on this
matter would pray to God. We must search for the rational causes,

and the causes are seen to be clear, and the method of prevention
also. He then proceeds to notice how all this arose from the

general reluctance to marriage and to bearing the expense of
educating a large family which resulted from the carelessness and

avarice of the men of his day, and he explains on entirely rational
principles the whole of this apparently supernatural judgment.

Now, it is to be borne in mind that while his rejection of miracles
as violation of inviolable laws is entirely A PRIORI - for

discussion of such a matter is, of course, impossible for a
rational thinker - yet his rejection of supernatural intervention

rests entirely on the scientific grounds of the necessity of
looking for natural causes. And he is quite logical in maintaining

his position on these principles. For, where it is either
difficult or impossible to assign any rational cause for phenomena,

or to discover their laws, he acquiesces reluctantly in the
alternative of admitting some extra-natural interference which his

essentiallyscientific method of treating the matter has logically
forced on him, approving, for instance, of prayers for rain, on the

express ground that the laws of meteorology had not yet been
ascertained. He would, of course, have been the first to welcome

our modern discoveries in the matter. The passage in question is
in every way one of the most interesting in his whole work, not, of

course, as signifying any inclination on his part to acquiesce in
the supernatural, but because it shows how essentiallylogical and

rational his method of argument was, and how candid and fair his
mind.

Having now examined Polybius's attitude towards the supernatural
and the general ideas which guided his research, I will proceed to

examine the method he pursued in his scientificinvestigation of
the complexphenomena of life. For, as I have said before in the

course of this essay, what is important in all great writers is not
so much the results they arrive at as the methods they pursue. The

increased knowledge of facts may alter any conclusion in history as
in physical science, and the canons of speculativehistorical

credibility must be acknowledged to appeal rather to that
subjective attitude of mind which we call the historic sense than

to any formulated objective rules. But a scientific method is a
gain for all time, and the true if not the only progress of

historical criticism consists in the improvement of the instruments
of research.

Now first, as regards his conception of history, I have already
pointed out that it was to him essentially a search for causes, a

problem to be solved, not a picture to be painted, a scientific
investigation into laws and tendencies, not a mere romanticaccount

of startlingincident and wondrous adventure. Thucydides, in the
opening of his great work, had sounded the first note of the

scientificconception of history. 'The absence of romance in my
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 rationalconsequent, 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
scientificinvestigator, 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 scientificcalculation. It is the latter
which are important for the establishing of principles and the

elucidation of the sequences of rationalevolution.
He thus may be said to have anticipated one of the most important

truths of the modern methods of investigation: I mean that
principle which lays down that just as the study of physiology

should precede the study of pathology, just as the laws of disease
are best discovered by the phenomena presented in health, so the

method of arriving at all great social and political truths is by
the investigation of those cases where development has been normal,

rational and undisturbed.
The critical canon that the more a people has been interfered with,

the more difficult it becomes to generalise the laws of its
progress and to analyse the separate forces of its civilisation, is

one the validity of which is now generally recognised by those who
pretend to a scientifictreatment of all history: and while we

have seen that Aristotle anticipated it in a general formula, to
Polybius belongs the honour of being the first to apply it

explicitly in the sphere of history.
I have shown how to this great scientifichistorian the motive of

his work was essentially the search for causes; and true to his
analytical spirit he is careful to examine what a cause really is

and in what part of the antecedents of any consequent it is to be
looked for. To give an illustration: As regards the origin of the

war with Perseus, some assigned as causes the expulsion of