Two ways of looking at authority have dominated over the past seven hundred or so years.
The first theory is back of the American Constitution: social contract theory. The idea is that at some point in the past “we” (our nation, or city, or human society in general) decided to trade some personal liberty for the security of laws that restrict all of us from doing whatever we want. This view of the world owes a lot to John Locke, who wrote of a primeval “state of nature” in which isolated humans roamed around, doing whatever they pleased, each looking out for number one. (This state of nature probably never existed, but we’ll go with it.) Then humans figured out that they could do better, and they entered into a “social contract,” an agreement to respect “rights” like property, life, and freedom and punish those who violated others’ rights. This social contract is the source of all political authority.
What this theory does pretty well is explain why political authority is “alienated” (it makes demands on me ) and yet still somehow “my good”. Following certain rules is my decision, as part of a certain culture or human society in general, even though I don’t feel like it at the moment. Long ago we made a decision, and that decision remains in force despite our changing whims. By way of example, let’s say I buy an expensive ticket to a concert, but at the last minute I get sick (or sick of the band) and don’t want to go. The ticket is non-refundable. If I don’t go, I face the pain of losing my money. If I do go, I face the pain of doing something I no longer want to do. The fact that I paid money already and have the ticket in my hand tells me: this was my decision. Social contract theory tells me that these rules, laws, rights, etc. are my rules, laws, and rights – alienated rules, laws, and rights.
What this theory does very badly is show that the social contract’s authoroity enforces “the good” – what is actually, objectively right and beneficial. Knowing that I bought my concert ticket – that it was my decision – does not assure me that I’ll go to the concert when I go to it. Knowing that the Founding Fathers thought democracy was a good way to run a nation may tell me why, historically, I live in a democracy, but it can’t possibly prove that they were right in the first place. What makes the laws of a long time ago any better than the laws and ideas of today? Why, for instance, keep an 18th century “right to keep and bear arms” when our culture and technology have changed drastically since then (as in, we have machine guns and bombers now)?
For this reason there is ongoing tension in the USA between advocates of a “living document” view of the Constitution and “strict constructionists”. Both agree that right and wrong are up to us. The strict constructionists think it best to put the brakes on change. The revisionists think change is an improvement. But their basic assumption is the same: the rules are what we decide(d) they are. Both are subject to the same authority problem: social contract theory explains why “the rules” bind me, but they do nothing to show that they are good. (That must come from some source completely outside of political theory.)