Nor can this be a matter of surprise. For, as the motive power is not transmitted from the agent to the patient, it remains whole and entire in the agent, however much it may be exerted in all directions. It is not absorbed, or exhausted, or weakened by its exertions, and, while acting on any number of terms, is yet ready to act on any number of other terms as intensely as it would on each of them separately. If ten new planets were now created, the sun would need no increase of power to attract them all; its actual power would suffice to govern their course without the least interference with the gravitation of the other existing planets. And the reason of this is that the power of all material elements is naturally determined to act, and therefore needs no other condition for its exertion than the presence of the movable terms within the reach of its activity. The number of such terms is therefore at every instant the measure of the number of the real actions. We have said that the active power is not weakened by its exertions. In fact, a cause is never weakened by the mere production of its connatural effects, but only because, while producing its effects, it is subjected to the action of other agents which tends to alter and break up its natural constitution. Now, to be altered and impaired may be the lot of those causes whose causality arises from the conspiration of many active principles, as is the case with all the physical compounds. But primitive causes, such as the first elements of matter, are altogether unalterable and incorruptible with respect to their substantial being, and can never be impaired. When we burn a piece of paper, the paper with its composition is destroyed, but we know that its first components remain unaltered, and preserve still the same active powers which they possessed when they were all united in the piece of paper.