302 HARVARD LAW REVIEW. rough one, and is exposed to many disturbing causes. I hope to say something at a future time of the methods by which it is effected in the system of the Common Law. Meanwhile it is to be remembered that the poHtical sciences do not claim to be exact in either a speculative or a practical point of view. For the prac- tical purposes of a State governed according to law, that degree of certainty suffices which will satisfy the citizens that the law works on the whole justly and without favor; and in archaic soci- eties not only is a pretty rough kind of certainty sufficient, but no other is possible. Rules of law have to be applied to the facts ascertained by the tribunal. Now the facts are often in dispute; indeed, those cases are a small minority where there is a real difference between the parties, and that difference turns merely upon the application of the law to undisputed facts. Much of the work done by the ma- chinery of justice consists in enforcing just claims to which there is no defence, but mere refusal or neglect to pay one's debts with- out compulsion of law does not constitute a real matter in difference. And the process of forming a judgment as to the truth of the facts, where conflicting accounts are offered, is itself an approximate one at best for human faculties. In early stages of legal institutions we find that there is hardly so much as a serious attempt in this direction ; the matters at issue are disposed of by methods which seem to us at this day not only artificial and inadequate, but out of all relation to any grounds of reasonable conclusion. The task would indeed seem to have been thought above the power of mor- tals. Ordeal in its various forms is a direct appeal to supernatural aid in the supposed incompetence of human understanding. Proof by oath, where the oath is conclusive, — a procedure of which the mediaeval ** compurgation " is the best known example, — is the same thing in a milder form. Wherever and so long as the facts cannot be ascertained with any precision, there is no occasion for precise or elaborate rules of law. The law cannot be more finely graduated than the means of ascertaining facts; and the judicial investigation of facts with something approaching completeness and exactness dates only from relatively modern times. Hence the development of law is largely bound up with the development of procedure. As improved procedure enables the law to grapple with complex facts, the aspirations of lawyers and citizens are en- larged, and they are by no means content to aim at the minimum of certainty which will insure public acquiescence in the justice of
