Injunctions not infrequently are granted as an equitable relief against a legal judgment. _Summum jus, summa injuria_ is an ancient maxim of the courts. The foundation of equitable jurisdiction is that courts of law cannot always do justice. One may, for instance, be invited to build a house on another's land, and promised a deed of the site. He builds the house and then is refused a deed. The invitation and promise were by word of mouth. The rules of law make such a house the legal property of the landowner. The rules of equity make it the equitable property of the man who built it on the faith of the landowner's invitation and promise. If the latter sue at law for the possession of the house, he may get judgment, but equity will prevent his enforcing the judgment, not because it is not a legal judgment, but because he is endeavoring to make an inequitable use of a legal right. A court of equity sometimes makes a decree establishing a title. To enforce such a judgment, a writ may be issued, called a writ of assistance. It is directed to the sheriff and requires him to do some specific act, such as putting the defendant out of possession of certain lands and turning it over to the plaintiff. It is, as appears from instances which have been given, possible that the execution of process from the courts may be defeated by violence which they cannot overcome. It is possible in fact though impossible in theory. As the sheriff can employ the _posse comitatus_, he ought always to have an overwhelming force at his command. But it is easier to "call spirits from the vasty deep" than to make them respond. Public feeling may be so strong in opposition to the service of the process that mob violence will be tolerated and even openly supported. An armed mob can only be effectually met by an armed force which is not a mob--that is, by disciplined soldiers. The sheriff, if so opposed, may call upon the Governor of the State for military assistance. How efficient it will prove will, of course, depend on the discipline of the militia and the firmness of its commanding officers. It is seldom that it fails to restore order, if the men carry loaded guns and are directed to fire at the first outbreak of forcible resistance. But the Governor may refuse to comply with the sheriff's request. In such case, the execution of the process of the court fails because of want, not of power, but of the will to exercise it on the part of those on whom that duty rests. In every government constituted by a distribution of the supreme authority between different departments, each of them must do its part loyally with respect to the others, or the whole scheme, for the time being, breaks down.