The Emperor Antoninus Pius, in one of his rescripts, said there was but little justice in claiming interest upon money after a long period; for the length of time elapsed was an indication that the debtor had been excused from payment, from some motive of kindness. There appears something similar to this in the nature of custom. For apart from the authority of civil laws, which regulate the time and manner of custom, and its introduction, it may arise from the indulgence of a sovereign to a conquered people. But the length of time from which custom derives the force of right, is not defined, but left to the arbitrary decision of what is sufficient to indicate general consent. But for silence to be taken as a valid presumption that property is deserted, two things are requisite: it must be a silence with a knowledge of the fact, and with a perfect freedom of will in the person concerned. For a silence founded in ignorance can have no weight; and where any other reason appears, the presumption of free consent must fail. VI. Although the two requisites already named may be produced, yet other reasons have their weight; among which length of time is not the least important. For in the first place, it can scarcely happen, that for a great length of time a thing belonging to any one should not some way or other come to his knowledge, as time might supply many opportunities. Even if the civil law did not interpose to bar remote pretensions, the very nature of things would shew the reasonableness of a shorter period of limitation being allowed to present than to absent claimants. If impressions of fear were pleaded by any one in excuse, yet their influence would not be of perpetual duration, and length of time would unfold various means of security against such fears, either from resources within himself, or from the assistance of others. Escaping beyond the reach of him he dreaded, he might protest against his oppression, by appealing to proper judges and arbitrators. VII. Now as time immemorial, considered in a moral light, seems to have no bounds, silence for such a length of time appears sufficient to establish the presumption that all claim to a thing is abandoned, unless the strongest proofs to the contrary can be produced. The most able Lawyers have properly observed, that time according to the memory of man is not an hundred years, though probably it may not fall far short of that space. For a hundred years are the term beyond which human existence seldom reaches; a space, which in general completes three ages or generations of men. The Romans made this objection to Antiochus, that he claimed cities, which neither he himself, his father, nor his grandfather had ever possessed.