[f] Hob. 85.
When a custom is actually proved to exist, the next enquiry is into the legality of it; for if it is not a good custom it ought to be no longer used. "Malus usus abolendus est" is an established maxim of the law[g]. To make a particular custom good, the following are necessary requisites.
[g] Litt. §. 212. 4 Inst. 274.
1. That it have been used so long, that the memory of man runneth not to the contrary. So that if any one can shew the beginning of it, it is no good custom. For which reason no custom can prevail against an express act of parliament; since the statute itself is a proof of a time when such a custom did not exist[h].
[h] Co. Litt. 113 b.
2. It must have been continued. Any interruption would cause a temporary ceasing: the revival gives it a new beginning, which will be within time of memory, and thereupon the custom will be void. But this must be understood with regard to an interruption of the right; for an interruption of the possession only, for ten or twenty years, will not destroy the custom[]. As if I have a right of way by custom over another's field, the custom is not destroyed, though I do not pass over it for ten years; it only becomes more difficult to prove: but if the right be any how discontinued for a day, the custom is quite at an end.
[] Co. Litt. 114 b.
3. It must have been peaceable, and acquiesced in; not subject to contention and dispute[k]. For as customs owe their original to common consent, their being immemorially disputed either at law or otherwise is a proof that such consent was wanting.
[k] Co. Litt. 114.
4. Customs must be reasonable[l]; or rather, taken negatively, they must not be unreasonable. Which is not always, as sir Edward Coke says[m], to be understood of every unlearned man's reason, but of artificial and legal reason, warranted by authority of law. Upon which account a custom may be good, though the particular reason of it cannot be assigned; for it sufficeth, if no good legal reason can be assigned against it. Thus a custom in a parish, that no man shall put his beasts into the common till the third of october, would be good; and yet it would be hard to shew the reason why that day in particular is fixed upon, rather than the day before or after. But a custom that no cattle shall be put in till the lord of the manor has first put in his, is unreasonable, and therefore bad: for peradventure the lord will never put in his; and then the tenants will lose all their profits[n].