'II. We must say according to this system that the body of Julius Caesar did so exercise its moving faculty that from its birth to its death it went through continual changes which did most exactly answer the perpetual changes of a certain soul which it did not know and which made no impression on it. We must say that the rule according to which that faculty of Caesar's body performed such actions was such, that he would have gone to the Senate upon such a day and at such an hour, that he would have spoken there such and such words, etc., though God had willed to annihilate his soul the next day after it was created. We must say that this moving power did change and modify itself exactly according to the volubility of the thoughts of that ambitious man, and that it was affected precisely in a certain manner rather than in another, because the soul of Caesar passed from a certain thought to another. Can a blind power modify itself so exactly by virtue of an impression communicated thirty or forty years [40] before and never renewed since, but left to itself, without ever knowing what it is to do? Is not this much more incomprehensible than the navigation I spoke of in the foregoing paragraph? 'III. The difficulty will be greater still, if it be considered that the human machine contains an almost infinite number of organs, and that it is continually exposed to the shock of the bodies that surround it,[1] and which by an innumerable variety of shakings produce in it a thousand sorts of modifications. How is it possible to conceive that this _pre-established harmony_ should never be disordered, but go on still during the longest life of a man, notwithstanding the infinite varieties of the reciprocal action of so many organs upon one another, which are surrounded on all sides with infinite corpuscles, sometimes hot and sometimes cold, sometimes dry and sometimes moist, and always acting, and pricking the nerves a thousand different ways? Suppose that the multiplicity of organs and of external agents be a necessary instrument of the almost infinite variety of changes in a human body: will that variety have the exactness here required? Will it never disturb the correspondence of those changes with the changes of the soul? This seems to be altogether impossible. [1] 'According to M. Leibniz what is active in every substance ought to be reduced to a true unity. Since therefore the body of every man is composed of several substances, each of them ought to have a principle of action really distinct from the principle of each of the others. He will have the action of every principle to be spontaneous. Now this must vary the effects _ad infinitum_, and confound them. For the impression of the neighbouring bodies must needs put some constraint upon the natural spontaneity of every one of them.'