As there is no bargaining possible with physical necessity, man must also, in spite of his liberty, feel what nature desires him to feel. According as it awakens in him a painful or an agreeable sensation, there will infallibly result in him either aversion or desire. Upon this point man quite resembles the brute; and the stoic, whatever his power of soul, is not less sensible of hunger, and has no less aversion to it, than the worm that crawls at his feet. But here begins the great difference: with the lower creature action succeeds to desire or aversion quite as of necessity, as the desire to the sensation, and the expression to the external impression. It is here a perpetual circle, a chain, the links of which necessarily join one to the other. With man there is one more force—the will, which, as a super-sensuous faculty, is not so subject to the law of nature, nor that of reason, that he remains without freedom to choose, and to guide himself according to this or to that. The animal cannot do otherwise than seek to free itself from pain; man can decide to suffer. The will of man is a privilege, a sublime idea, even when we do not consider the moral use that he can make of it. But firstly, the animal nature must be in abeyance before approaching the other, and from that cause it is always a considerable step towards reaching the moral emancipation of the will to have conquered in us the necessity of nature, even in indifferent things, by the exercise in us of the simple will. The jurisdiction of nature extends as far as the will, but there it stops, and the empire of reason commences. Placed between these two jurisdictions, the will is absolutely free to receive the law from one and the other; but it is not in the same relation with one and the other. Inasmuch as it is a natural force it is equally free with regard to nature and with respect to reason; I mean to say it is not forced to pass either on the side of one or of the other: but as far as it is a moral faculty it is not free; I mean that it ought to choose the law of reason. It is not chained to one or the other, but it is _obliged_ towards the law of reason. The will really then makes use of its liberty even whilst it acts contrary to reason: but it makes use of it unworthily, because, notwithstanding its liberty, it is no less under the jurisdiction of nature, and adds no real action to the operation of pure instinct; for to will by virtue of _desire_ is only to desire in a different way. There may be conflict between the law of nature, which works in us through the instinct, and the law of reason, which comes out of principles, when the instinct, to satisfy itself, demands of us an action which disgusts our moral sense. It is, then, the duty of the will to make the exigencies of the instinct give way to reason. Whilst the laws of nature oblige the will only conditionally, the laws of reason oblige absolutely and without conditions.