48o HARVARD LAW REVIEW. haps no satisfactory definition has yet been given. Some essentials, however, may be readily determined without much discussion. For example, it will be agreed that law in this sense is a standard of conduct for human beings, and also that it is prescribed by the community through its constituted authorities. The agreement in definition would perhaps stop here ; ^ but a definition containing no more than that would lack at least one element that should properly be contained in it. If municipal law in the sense indicated is to be the subject matter of jurisprudence, which is a science compar- able to, and with an assured position among, the other sciences,^ it must be capable of scientific treatment, or, in other words, must be rational. It might conceivably exist and be irrational ; but in that event there could certainly be no science of it, and therefore no jurisprudence. It follows that in every juridical discussion in which there is anything more than affirmation on one side and negation on the other, there is necessarily implied as one of its conditions the rational character of the law. Law, to be rational, must be founded upon a reason. If no rea- son should in fact exist, law would have no support but the power of the legislating community. It might, it is true, exist under such conditions, but it is also true that it would then lack certain im- portant characteristics usually associated with law. It would lack, for example, every characteristic of permanence and stability. It might change at any moment, according to the shifting will of the community which prescribes it, and still maintain whatever validity as law it originally possessed, for by hypothesis it would have no reason, and therefore would have no reason for being one thing 1 Compare the following definitions : — Law is " a rule of civil conduct prescribed by the supreme power in a state, com- manding what is right and prohibiting what is wrong." i Bl. Comm. 44. It is " a general rule of external human action enforced by a sovereign political authority." Holland, Juris. 37. " It is the body of commands issued by the rulers of a political society to its mem- bers, which lawyers call by the name * law.' " Markby, Elem. of Law, § 5. " Every positive law, or every law simply and strictly so called, is set by a sovereign person, or sovereign body of persons, to a member or members of the independent political society wherein that person or body is sovereign or supreme." Austin, Juris., Lect. VI. sec. 189. "Rules of [law] are the rules which are deemed binding on the members of the state as such, and are administered, as and because thus binding, by courts of justice." Pollock, First Book of Juris. 55. Many more definitions might be cited ; but these will suffice to show how great a variety of form may be combined with similarity of substance. 2 See Bouv. Law Diet, sicb voc, and references.
