The reason of the law ceasing, the law itself ceases.
When the law casts upon an individual, or body of persons, the burden of particular duties, it clothes them also with the means of performing those duties, but so long only as they are in the performance of those duties have they the protection of the law ; and the moment the reason of their being so protected ceases, the protection so afforded to them by the law also ceases. This may be familiarly instanced in the protection from all civil process given to a foreign ambassador whilst in the exercise of the duties of his office in this country ; to members of Parliament during the sitting of Parliament ; to all judges exercising their judicial functions ; to banisters attending the courts of law and equity ; to attorneys, solicitors, and other officers of the several courts of law and equity ; and to sheriffs and others acting in the administration of the law, and in which they are by law authorised and required so to act : and the reason in these particular cases is, that such protection is necessary for the performance by them of their respective duties, but the moment they cease to be so acting the protection so afforded to them also ceases.
The maxim is applicable also as well to things as to persons. Things may be called property, and to all property there are rights and duties incident. Of all property, also, there is of necessity a proprietor, upon whom devolves as 'well the rights as the duties incident to the property, according to its particular nature and use, and for the due performance of which rights and duties he is responsible to the law so long as he continues to be 'such proprietor ; but so soon as the property passes from him, the incidents connected therewith which the law attaches thereto also pass. So it is upon the destruction of the property, or the diversion of it from a particular use. Upon its destruction the rights and duties attached to it are destroyed, and upon its diversion from one use to another such rights and duties are also diverted.
All lands in England were at one time held upon condition of the performance by the holder or feoffee of some military or other services, and those services were attached to the land, and followed it upon each successive change into the hands of .each succeeding holder or feoffee, and continued subject to the same or other services according to the will of the feoffor or lord. Such grants being made originally by the king to his followers for warlike services, the necessity for such a mode of payment ceasing, the use of the land was allowed to be diverted, and the land itself to be granted out upon other conditions ; still, however, subject to conditions, being those rights and duties which the law attaches to it, and which it can at any time attach to, or take away. A right of common, in the present day, is one which the law both gives and takes away ; the common law gives the right of common to the owner of the adjoining land, and the law by legislative enactment takes it away, by diverting its purpose, and making what was before merely a right, a realty ; there being no more any reason why such common lands should exist, but rather a reason to the contrary, the law interferes and alters their nature, by directing that what was before common to all, should be appropriated equally to each.
So in all cases of privilege granted by the law, and of Acts of Parliament become obsolete ; for, when the reason for their institution ceases, they themselves also cease.
The maxim “ Oessante causa, cessat effectus,'' is to the same purpose.
Co.Litt. 70; Shepp. Touch. 287; Noy Max. 5; Plowd.268; Whelpdale's Case, 5 Co. 119 ; 11 Co. 49 ; 13 Co. 38 ; Davis v. Powell and others, Willes, 46 ; Goody v. Duncombe, 1 Exch. 430 ; Bromfield v. Kirber, 11 Mod. 72 Jones v. Robin, 10 Q. B. 581 ; Prichard v. Powell and others, 10 Q. B. 589 Heath v. Elliott, 4 Bing. N. C. 388 ; Gullett v. Lopes, Bart., 13 East, 348 Richards v. Heather, 1 B. & Aid. 29-33 ; Wells v. Pearcey, 1 N. C. 556.