he former case the relation of God to the world is
made an external relation; in the latter, an internal one. In the one the
world is thought of as a clock, which once wound up runs on mechanically,
in the second it is likened to a piece of music which the composer himself
recites. If God preserves created things by continually recreating them
they are not substances at all; if they are substances, preservation
becomes an empty word, which we repeat after the theologians without giving
it any real meaning.

Matter and spirit stand related in our thought only by way of exclusion;
is the same true of them in reality? They can be conceived and can exist
without each other; can they, further, without each other effect all that
we perceive them to accomplish? There are some motions in the material
world which we refer to a voluntary decision of the soul, and some among
our ideas (_e.g._, perceptions of the senses) which we refer to corporeal
phenomena as their causes. If body and soul are substances, how can they
be dependent on each other in certain of their activities, if they are of
opposite natures, how can they affect each other? How can the incorporeal,
unmoved spirit move the animal spirits and receive impulses from them?
The substantiality (reciprocal independence) of body and mind, and their
interaction (partial reciprocal dependence), are incompatible, one or
the other is illusory and must be abandoned. The materialists (Hobbes)
sacrifice the independence of mind, the idealists (Berkeley, Leibnitz), the
independence of matter, the occasionalists, the interaction of the two.
This forms the advance of the last beyond Descartes, who either naively
maintains that, in spite of the contrariety of material and mental
substances, an exchange of effects takes place between them as an
empirical fact, or, when he realizes the difficulty of the anthropological
problem,--how is the union of the two substances in man possible,--ascribes
the interaction of body and mind, together with the union of the two, to
the power of God, and by this abandonment of the attempt at a natural
explanation, opens up the occasionalistic way of escape. Further, in
his more detailed description of the intercourse between body and mind
Descartes had been guilty of direct violations of his laws of natural
philosophy. If the quantity of motion is declared to be invariable and a
change in its direction is attributed to mechanical causes alone, we must
no