On similar ground it may be proved that no society can make a perpetual constitution, or even a perpetual law. The earth belongs always to the living generation. They may manage it then, and what proceeds from it, as they please, during their usufruct. They are masters too of their own persons, and consequently may govern them as they please. But persons and property make the sum of the objects of government. The constitution and the laws of their predecessors extinguished then in their natural course with those who gave them being. This could preserve that being till it ceased to be itself, and no longer. Every constitution then, and every law, naturally expires at the end of 19 years. If it be enforced longer, it is an act of force, and not of right.--It may be said that the succeeding generation exercising in fact the power of repeal, this leaves them as free as if the constitution or law has been expressly limited to 19 years only. In the first place, this objection admits the right, in proposing an equivalent. But the power of repeal is not an equivalent. It might be indeed if every form of government were so perfectly contrived that the will of the majority could always be obtained fairly and without impediment. But this is true of no form. The people cannot assemble themselves. Their representation is unequal and vicious. Various checks are opposed to every legislative proposition. Factions get possession of the public councils. Bribery corrupts them. Personal interests lead them astray from the general interests of their constituents: and other impediments arise so as to prove to every practical man that a law of limited duration is much more manageable than one which needs a repeal.
http://press-pubs.uchicago.edu/founders ... h2s23.html
He believed it was best for all laws and constitutions to expire every 19 years. Do you believe the laws should expire, and if so how long should any given law last?