[CHAPTER XIII.]
ACTIVITY.
129. To understand more clearly the idea of causality, it will be useful to reflect on the ideas of activity and action, as also on those of inertness, or inactivity, and inaction.
130. An absolutely inactive being is a being without intelligence, without will, without sensibility, without any kind of consciousness, containing in itself nothing which can change its own state or that of any thing else.
Thus absolute inactivity or inertness requires the following conditions: I. The absolute denial of all principle, of intelligence, of will, of sensibility, and in general of every thing which is accompanied by consciousness. II. The absolute denial of all principle of change in itself. III. The absolute denial of all principle of change in others. The union of these three conditions forms the idea of absolute inactivity or inertness: the state of such a being is that of absolute inaction.
131. A being of this nature, regarded in general, presents only the idea of an existing thing: we may also consider it as a substance, supposing it not to inhere as a modification in another, or rather, supposing it as a substratum capable of receiving modifications by the action of other beings upon it.
The only means by which we can characterize to a certain extent this general idea, so that it may be presented to our intuition, is to add to it the idea of extension, by which we make in some manner the idea of inert matter.
132. After the ideas of inertness and inaction are explained, their opposites, the ideas of activity and action, are clearly understood.