in the first fact, it cannot be in any; for necessity cannot be formed little by little, and by successive increment. If, at the first murder that I see, I do not exclaim that this murder necessarily has a cause, at the thousandth murder, although it shall have been proved that all the others have had causes, I shall have the right to think that this new murder has, very probably, also its cause; but I shall never have the right to declare that it necessarily has a cause. But when necessity and universality are already in a single case, that case alone is sufficient to entitle us to deduce them from it.[30] We have established the existence of universal and necessary principles: we have marked their origin; we have shown that they appear to us at first from a particular fact, and we have shown by what process, by what sort of abstraction the mind disengages them from the determinate and concrete form which envelops them, but does not constitute them. Our task, then, seems accomplished. But it is not,--we must defend the solution which we have just presented to you of the problem of the origin of principles against the theory of an eminent metaphysician, whose just authority might seduce you. M. Maine de Biran[31] is, like us, the declared adversary of the philosophy of sensation,--he admits universal and necessary principles; but the origin which he assigns to them, puts them, according to us, in peril, and would lead back by a _detour_ to the empirical school. Universal and necessary principles, if expressed in propositions, embrace several terms. For example, in the principle that every phenomenon supposes a cause; and in this, that every quality supposes a substance, by the side of the ideas of quality and phenomenon are met the ideas of cause and substance, which seem the foundation of these two principles. M. de Biran pretends that the two ideas are anterior to the two principles which contain them, and that we at first find these ideas in ourselves in the consciousness that we are cause and substance, and that, these ideas once being thus acquired, induction transports them out of ourselves, makes us conceive causes and substances wherever there are phenomena and qualities, and that the principles of cause and substance are thus explained. I beg pardon of my illustrious friend; but it is impossible to admit in the least degree this explanation. The possession of the origin of the idea of cause is by no means sufficient for the possession of the origin of the principle of causality; for the idea and the principle are things essentially different. You have established, I would say to M. de Biran, that the idea of cause is found in that of productive volition:--you will to produce certain effects, and you produce them; hence the idea of a cause, of a particular cause, which is yourself; but between this fact and the axiom that all phenomena which appear necessarily have a cause, there is a gulf.