[435]. An easement, in the strictest sense, means a particular kind of servitude, namely a private and appurtenant servitude which is not a right to take any profit from the servient land. A right of way or of light or of support is an easement; but a right to pasture cattle or to dig for minerals is in English law a distinct form of servitude known as a profit. This distinction is unknown in other systems, and it has no significance in juridical theory. Its practical importance lies in the rule that an easement must (it seems) be appurtenant, while a profit may be either appurtenant or in gross.
[436]. The term security is also used in a wider sense to include not only securities over property, but also the contract of suretyship or guarantee—a mode of ensuring the payment of a debt by the addition of a second and accessory debtor, from whom payment may be obtained on default of the principal debtor. With this form of security we are not here concerned, since it pertains not to the law of property, but to that of obligations.
[437]. The word lien has not succeeded in attaining any fixed application as a technical term of English law. Its use is capricious and uncertain, and we are at liberty, therefore, to appropriate it for the purpose mentioned in the text, i.e., to include all forms of security except mortgages.
[438]. As we shall see, a mortgage by way of transfer is none the less an encumbrance also—an encumbrance, that is to say, of the beneficial ownership which remains vested in the mortgagor.
[439]. It is not essential to a mortgage that the right vested in the mortgagee should in actual fact survive the right secured by it, so as to remain outstanding and redeemable. It is sufficient that in its nature it should be capable of doing so, and therefore requires to be artificially restricted by an obligation or condition of re-assignment or surrender. This re-assignment or surrender may be effected by act of the law, no less than by the act of the mortgagee. The conveyance of the fee simple of land by way of security is necessarily a mortgage and not a lien, whether it revests in the mortgagor ipso jure on the payment of the debt, or does not revest until the mortgagee has executed a deed of reconveyance.
[440]. This is one of the reforms effected by the Torrens system of real property law in force in the Australasian colonies. The so-called mortgages of land under that system are in reality merely liens.
[441]. Applications of the rule of possessory ownership may be seen in the cases of Armory v. Delamirie, 1 Str. 504; 1 Smith, L. C. 343; Asher v. Whitlock, L. R. 1 Q. B. 1; and Perry v. Clissold, (1907) A. C. 73.
[442]. The term prescription (praescriptio) has its origin in Roman law. It meant originally a particular part of the formula or written pleadings in a law suit—that portion, namely, which was written first (praescriptum) by way of a preliminary objection on the part of the defendant. Praescriptio fori, for example, meant a preliminary plea to the jurisdiction of the court. So praescriptio longi temporis was a plea that the claim of the plaintiff was barred by lapse of time. Hence, by way of abbreviation and metonymy (other forms of prescription being forgotten) prescription in the modern sense.
[443]. It is clear, however, that until a debt or other obligation is actually due and enforceable, no presumption against its validity can arise through the lapse of time. Therefore prescription runs, not from the day on which the obligation first arises, but from that on which it first becomes enforceable. Agere non valenti non currit praescriptio.
[444]. C. 2. 3. 20.