Because see, the reality is, very few individuals are willing to say something like this: I believe in the teachings of Jesus (or of John Maynard Keynes, for that matter) because I am an authoritative judge of teachings. Instead, in defending those things we think of as authoritative, we appeal to external evidence. We try to make Jesus or Keynes the authority, we try to move ourselves out of the way.
I'm mired in early American literature, so the question is most pronounced with regard to the teachings of Jesus. The question is, why is the sermon on the mount authoritative? And keep in mind, you're being stupid if you just shrug right now and say, "Well I don't think Jesus' teachings are authoritative," because that's not what I'm asking.
So here are some various thoughts I've culled together out of the 17th, 18th, and 19th centuries:
According to Philip Gura's really good recent book, American Transcendentalism, around 1836, a guy named Theodore Parker (a unitarian minister/scholar) "sought to answer this question: 'Do men believe in Christianity SOLELY on the ground of miracles?" Parker, not incidentally, believed that men should not believe by reason of the miracles: "I need no miracle to convince me that the sun shines... nor of the divinity of Jesus and his doctrines" (qtd. in Gura).
Jonathan Edwards (of "Sinners in the Hands of an Angry God" fame) framed the question differently, but again in terms of Jesus' authority. In an awesome sermon/essay called "A Divine and Supernatural Light," Edwards begins with a text from Matthew 16:17: "And Jesus answered and said unto him, Blessed art thou, Simon Barjona; for flesh and blood hath not revealed it unto thee, but my Father which is in heaven." Edwards riffs on this theme to argue, anticipating Parker, that the teachings of Jesus are intrinsically authoritative. That is, we must recognize them immediately, and without reference to history, as "divine."
To bring this question to life for my students, I often ask, "What would happen if all we had was a transcript of what Jesus said at the sermon on the mount?" Almost universally, the conclude that his teachings would be far less authoritative if they were not accompanied by his life-narrative, including his miracles. To make sure they understand what they are saying, I show them two statements, the first from Jesus in the Gospel of Thomas, the second from Whitman's "Song of Myself":
1. I am the light that is over all things. I am all: from me all came forth, and to me all attained. Split a piece of wood; I am there.2. I bequeath myself to the dirt to grow from the grass I love, If you want me again look for me under your boot-soles.
Here the students become firmly committed to the view that the narrative is necessary. They say, "Without his miracles and his resurrection, Jesus would just be another wise teacher" (my emphasis).
But later in the essay, Edwards makes a s-weeeet move that I think seriously unsettles any of my students who are still paying attention here. He says, summarizing Luke 12:56-57, "Christ condemns the Jews, that they did not know that He was the Messiah, and that His doctrine was true, from an inward distinguishing taste and relish of what was divine." Then further on, paraphrasing Jesus' reproach of the Jews, Edwards continues, "Why have ye not that savor of the things of God, by which you may see the distinguishing glory, and evident divinity of me and my doctrine?"
In that part of the story, Jesus hasn't yet died and been resurrected -- so if knowing by a person's narrative, by "extrinsic signs," is a good way to recognize authoritative speech, Jesus shouldn't have blamed the Jews for not recognizing him.
So now the question looks like this: How would you recognize the divinity of Jesus? And the answer my students give (by his miracles) is essentially ineffective--is not an option. He will not glide in wearing a glowing white robe, 9 feet tall, and calling you "my child." He may not even have long hair, I tell them... or a beard... or a penis. I usually phrase that last part carefully, but I think I'm doing a fair interpretation of Edwards' and Parker's views. And of course, Emerson would say the same. I conclude by reading them Jesus own words:
"Stop judging by mere appearances, and make a right judgment." (John 7:24)
But for some reason, despite clear and convincing arguments about this, my students cannot cease to see the Bible itself as authoritative. Or the miracles. Or their church, or their ministers, or their parents. But in my view, these are the "false idols" warned against from the beginning of the Judeo-Christian tradition. Even the Word is not the highest authority, because there is never a situation where someone is not reading the Word. There is always an interpreter. To defer to a minister or scholar is to give-over to an obvious extrinsic evidence, is to put your faith in the minister and not in G-d. But even in reading the Bible, or our favorite book of French criticism, or our favorite political tract, if we forget that it is we who have favorites, who have preferences--if we forget that we are in the judges seat, then, according to Jesus, Jonathan Edwards, Theodore Parker, and R.W. Emerson--then, we are lost. The movement that continues into the contemporary era, popular among Evangelical and Reform Protestants, Sola Scriptura, explicitly opposes this view. The Sola Scriptura crowd places ultimate authority in the Bible, in its words. And I think it is only in understanding clearly and intensely just how wrong the Sola Scriptura crowd is that a person may begin to see the glory in its opposition: the Sola Fide approach.
Can I get a quick linguistic analysis of the word "antinomian," maybe? I suspect that this word, which Wikipedia translates "lawlessness," or "against the law," may also denote or connote something like "against the name," or even "against the doctrine." And the problem here is that most of us think that this means only "the law," as in jaywalking and smoking in restaurants and murder laws. But I think it also means propositional ethical teachings, even if they are not backed by the state. If someone brings ten commandments down from a mountaintop carved in stone, the carvings are not automatically authoritative, and nothing except each witnessing self can make them so. Moses can say "God told me thou shalt not," but thou must decide whether Moses and his teachings are insane, misguided, or authoritative.
So anyway, isn't that rich territory? Give it all up! All of it. Even Jesus, Edwards, Parker, and Emerson--and me, and this persuasive post. Because those are deeply external sources. But when you discover this minority (almost secret) view in yourself, don't be surprised if you are not the first to have tread that ground.