290. As for spontaneity, it belongs to us in so far as we have within us the source of our actions, as Aristotle rightly conceived. The [304] impressions of external things often, indeed, divert us from our path, and it was commonly believed that, at least in this respect, some of the sources of our actions were outside ourselves. I admit that one is bound to speak thus, adapting oneself to the popular mode of expression, as one may, in a certain sense, without doing violence to truth. But when it is a question of expressing oneself accurately I maintain that our spontaneity suffers no exception and that external things have no physical influence upon us, I mean in the strictly philosophical sense. 291. For better understanding of this point, one must know that true spontaneity is common to us and all simple substances, and that in the intelligent or free substance this becomes a mastery over its actions. That cannot be better explained than by the System of Pre-established Harmony, which I indeed propounded some years ago. There I pointed out that by nature every simple substance has perception, and that its individuality consists in the perpetual law which brings about the sequence of perceptions that are assigned to it, springing naturally from one another, to represent the body that is allotted to it, and through its instrumentality the entire universe, in accordance with the point of view proper to this simple substance and without its needing to receive any physical influence from the body. Even so the body also for its part adapts itself to the wishes of the soul by its own laws, and consequently only obeys it according to the promptings of these laws. Whence it follows that the soul has in itself a perfect spontaneity, so that it depends only upon God and upon itself in its actions. 292. As this system was not known formerly, other ways were sought for emerging from this labyrinth, and the Cartesians themselves were in difficulties over the subject of free will. They were no longer satisfied by the 'faculties' of the Schoolmen, and they considered that all the actions of the soul appear to be determined by what comes from without, according to the impressions of the senses, and that, ultimately, all is controlled in the universe by the providence of God. Thence arose naturally the objection that there is therefore no freedom. To that M. Descartes replied that we are assured of God's providence by reason; but that we are likewise assured of our freedom by experience thereof within ourselves; and that we must believe in both, even though we see not how it is possible to reconcile them.