BOOK I PART IV
ing and reflection, so these latter actions of the
mind are equally prejudicial to the former. The
mind, as well as the body, seems to be endowed
with a certain precise degree of force and activ-
ity, which it never employs in one action, but
at the expense of all the rest. This is more evi-
dently true, where the actions are of quite dif-
ferent natures; since in that case the force of the
mind is not only diverted, but even the dispo-
sition changed, so as to render us incapable of a
sudden transition from one action to the other,
and still more of performing both at once. No
wonder, then, the conviction, which arises from
a subtile reasoning, diminishes in proportion
to the efforts, which the imagination makes to
enter into the reasoning, and to conceive it in
all its parts. Belief, being a lively conception,
can never be entire, where it is not founded on
something natural and easy.