V. Relation to modifications is not inseparable from the ideas of being, permanence, and non-inherence in another.
VI. An immutable substance implies no contradiction.
VII. To subsist by itself is not the same as to be independent of all other beings. The relation of cause and effect ought not to be confounded with the relation of substance and accident.
VIII. Non-inherence in another is characteristic of substance; but this negative idea must be founded on something positive; on the force to subsist by itself without the necessity of adhering to another.
[CHAPTER XV.]
PANTHEISM EXAMINED IN THE ORDER OF IDEAS.
109. The idea of substance and all its applications, as well to the external as to the internal world, are far from leading us to infer the existence of a single substance; on the contrary, reason according with experience forces us to acknowledge a multitude of substances. Why should we admit only one substance? This is one of the most important questions of philosophy, and from the most ancient times has given occasion to the most serious errors; it consequently deserves a careful investigation.
110. Those who admit only one substance must found their opinion either on the idea of substance or on experience; our mind can have no other recourse than to its primitive ideas, or the teachings of experience. Let us begin with the a priori method or that which is founded on the idea.