the point where the English
writer abandoned its further analysis, to commence to apply that which
he had made to the history of various nations, that one might almost
suppose the two authors had undertaken the task conjointly, and divided
the work between them.

It was the purpose of Mr. Buckle, in his introduction, to ascertain the
sources of social, and, incidentally, of individual development--the
fundamental causes of human progression; and subsequently to verify the
principles established, by tracing, in general outlines, the rise and
advance of leading nations under their impulse. The basis upon which he
started in his examination was this: 'That when we perform an action, we
perform it in consequence of some motive or motives; that those motives
are the results of some antecedents; and that, therefore, if we were
acquainted with the whole of the antecedents, and with all the laws of
their movements, we could with unerring certainty predict the whole of
their immediate results.'

From this proposition the historian concludes 'that the actions of men,
being determined solely by their antecedents, must, under precisely the
same circumstances, always issue in precisely the same results. And as
all antecedents are either in the mind or out of it, we clearly see that
all the variations in the results--in other words, all the changes of
which history is full, all the vicissitudes of the human race, their
progress or their decay, their happiness or their misery--must be the
fruit of a double action; an action of external phenomena upon the mind,
and another action of the mind upon the phenomena.'

Mr. Buckle gives it as the result of his investigations concerning the
relative influence of these two agencies: That external or physical laws
have been most powerful in the earlier ages of the world, and among the
most ignorant nations; that in proportion as knowledge increases, the
power of this class of agencies diminishes, and that of mental laws
becomes more predominant; that these latter are therefore the great
motor forces of civilization, consisting of two parts, the moral and the
intellectual, of which the latter are vastly superior as instruments of
social advancement, stationary in their effects; finally, as the formal
statement of the laws of human development, he says:

'1st. That the progress of mankind depends on the success with
which the laws of phenomena are investigated, and on the extent to