precise scope of rules which it is our business to know.  It is a part of the rational study, because it is the first step toward an enlightened scepticism, that is, towards a deliberate reconsideration of the worth of those rules.  When you get the dragon out of his cave on to the plain and in the daylight, you can count his teeth and claws, and see just what is his strength.  But to get him out is only the first step.  The next is either to kill him, or to tame him and make him a useful animal.  For the rational study of the law the blackletter man may be the man of the present, but the man of the future is the man of statistics and the master of economics.  It is revolting to have no better reason for a rule of law than that so it was laid down in the time of Henry IV.  It is still more revolting if the grounds upon which it was laid down have vanished long since, and the rule simply persists from blind imitation of the past.  I am thinking of the technical rule as to trespass ab initio, as it is called, which I attempted to explain in a recent Massachusetts case.

Let me take an illustration, which can be stated in a few words, to show how the social end which is aimed at by a rule of law is obscured and only partially attained in consequence of the fact that the rule owes its form to a gradual historical development, instead of being reshaped as a whole, with conscious articulate reference to the end in view.  We think it desirable to prevent one man’s property being misappropriated by another, and so we make larceny a crime.  The evil is the same whether the misappropriation is made by a man into whose hands the owner has put the property, or by one who wrongfully takes it away.  But primitive law in its weakness did not get much beyond an effort to prevent violence, and very naturally made a wrongful taking, a trespass, part of its definition of the crime.  In modern times the judges enlarged the definition a little by holding that, if the wrong-doer gets possession by a trick or device, the crime is committed.  This really was giving up the requirement of trespass, and it would have been more logical, as well as truer to the present object of the law, to abandon the requirement altogether.  That, however, would have seemed too bold, and was left to statute.  Statutes were passed making embezzlement a crime.  But the force of tradition caused the crime of embezzlement to be regarded as so far distinct from larceny that to this day, in some jurisdictions at least, a slip corner is kept open for thieves to contend, if indicted for larceny, that they should have been indicted for embezzlement, and if indicted for embezzlement, that they should have been indicted for larceny, and to escape on that ground.