One reason, of course, is that I am likely to be punished if I don't.
But we are looking here for a more principled reason for obeying.
Some political philosophers conclude that the problem is insoluble.
I should obey the law, they say, only when there are independent reasons to do so, reasons that have nothing to do with the fact that the law emanates from a legitimate authority.
But others have tried to provide positive solution-too many, in fact, for all of them to be considered here.
I shall look at just two, the first because it has historically been the most popular, the second because I believe it to be broadly correct.