t ascribe to the soul the power to move the pineal gland, even in the
gentlest way, nor to control the direction of the animal spirits. These
inconsistencies also are removed by the occasionalistic thesis.

The question concerning the substantiality of mind and matter in relation
to God, is involved from the very beginning in this latter problem, "How
is the appearance of interaction between the two to be explained without
detriment to their substantiality in relation to each other?" The denial
of the reciprocal dependence of matter and spirit leads to sharper
accentuation of their common dependence upon God. Thus occasionalism forms
the transition to the pantheism of Spinoza, Geulincx emphasizing the
non-substantiality of spirits, and Malebranche the non-substantiality of
bodies, while Spinoza combines and intensifies both. And yet history was
not obliging enough to carry out this convenient and agreeable scheme of
development with chronological accuracy, for she had Spinoza complete his
pantheism _before_ Malebranche had prepared the way. The relation which was
noted in the case of Bruno and Campanella is here repeated: the earlier
thinker assumes the more advanced position, while the later one seems
backward in comparison; and that which, viewed from the standpoint of the
question itself, may be considered a transition link, is historically to be
taken as a reaction against the excessive prosecution of a line of thought
which, up to a certain point, had been followed by the one who now shrinks
back from its extreme consequences. The course of philosophy takes first a
theological direction in the earlier occasionalists, then a metaphysical
(naturalistic) trend in Spinoza, to renew finally, in Malebranche, the
first of these movements in opposition to the second. The Cartesian school,
as a whole, however, exhibits a tendency toward mysticism, which was
concealed to a greater or less extent by the rationalistic need for clear
concepts, but never entirely suppressed.

Although the real interaction of body and mind be denied, some explanation
must, at least, be given for the appearance of interaction, _i.e._ for the
actual correspondence of bodily and mental phenomena. Occasionalism denotes
the theory of occasional causes. It is not the body that gives rise to
perception, nor the mind that causes the motion of the limbs which it has
determined upon--neither the one nor the other can receive influence from
its fellow or exe