no special application of Principles there elaborated was made to this
formula. It was there pointed out, that intellectual forces constitute
only _one_ of the factors in the sum of human progress, and that _moral_
forces are equally as important, being the second--the opposite and
complementary factor. In the light of that exposition, and of the brief
consideration here given to the second Generalization, it is perceptible
that the defect in this proposition consists, not in what it affirms,
but in what it does _not_ affirm. 'That the progress of mankind depends
on the success with which the laws of phenomena are investigated, and on
the extent to which a knowledge of those laws is diffused,' is a
statement which is undeniably true. It does not, however, contain the
_whole truth_ in relation to the subject of investigation. It is just as
correct to say that the progress of mankind depends on the success with
which the moral or religious faculties--faculties which instigate
devotion to our highest perception of right--are cultivated, and on the
extent to which they are practically active. For it is not in the
inculcation of intellectual truth alone, or preëminently, nor in the
cultivation of moral strength alone, or predominantly, that the progress
of mankind is secured; but in the developing vigor of _both_ mental and
moral forces, and in their mutual coöperation and assistance.

The proposition, as announced by Mr. Buckle, is, therefore, either a
half-truth, which does not sufficiently explain the cause of 'the
progress of mankind,' which the Historian avers that it unfolds, or it
is actually false, accordingly as it is understood to state a verity
which does not exclude the _affirmative_ statement of an opposite and
apparently antagonistic truth, or as it is interpreted to be the
explanation of the whole or main cause upon which the advancement of
society has depended. That the author of 'Civilization in England'
regarded it in this latter light, is plainly apparent. His whole work is