KEENER ON QUASI-CONTRACTS, 219 and a consideration of this suggested meaning is therefore neces- sary. It brings us back, however, to the indefiniteness of the thought itself. How can the law be a source of obligation? It is conceivable of course that the law may impose obligations -which have no reason outside of the law itself. Such an obligation would be a legal obligation, having its origin in the law, and in the law alone, and the law might then rightly be called the source of the obligation. Certainly there is no other source. But having no reason, such an obligation would be incapable of explanation and would have no more validity than the power of the government behind it. It would be in fact an arbitrary or tyrannical obliga- tion, and such obligations are not the subject-matter of jurispru- dence. This meaning of the phrase "imposed by law" in a sci- ence of jurisprudence therefore defeats itself and maybe neglected. If, on the other hand, the law acts in each case with a reason, the relation of law to that reason differs in no respect from the relation of law to the will of the parties in the case of legal contractual obligations. The will of the parties is, with those obligations, nothing but the reason of the law. In other words, the reason must exist antecedently to the law and the law is but the sanction of society added to the inherent force of the reason. The result is then that the notion of the law as a source of obligation means nothing more than a sanction applicable to all obligations, consen- sual and non-consensual alike. By obHgations imposed by law, there- fore, the learned author can intend only one of two things, either obligations carrying with them a legal sanction, that is, all legal obligations whatsoever, or else, as we have heretofore seen, a class of obligations marked only by the absence of the element of consent. Now, whichever of these two we take to be the meaning of the phrase " imposed by law," we find the opposition between the two classes which the author has created to rest fundamentally on the presence or absence of mutual assent, with the result that the class in which the assent is absent, the class of obligations imposed by law, that is to say, resolves itself in essence into a mere resid- uary class, formed on a principle of exclusion and containing with- in itself no element of generic likeness. But such a class as we have seen is not a true class and is not valuable in scientific classification. The subdivision of obligations imposed by law into obligations to act and obligations to forbear is logical enough because it is exhaustive, action and forbearance being antithetical and per-