Many people accuse Joseph Smith of being a charlatan. And to be honest, that perspective makes some sense: he told several different versions of his first vision story, hid his polygamy, and (according to some) changed the doctrine he taught in various phases over the course of his life. But there's a flaw in this argument. In fact, it's just because Joseph Smith was so "loose" with the truth that he can't have been a swindler after tithing money.
Here's my reasoning: if Joseph were really a "con man," he would have chosen a version of his first vision story and stuck with it. It's the same with the doctrine that changed over decades: if Joseph wanted to fool people, he could have done it a lot more easily by avoiding apparent contradictions between doctrines of the Godhead in his teachings. No, Joseph wasn't a swindler. A con-man can slip up by contradicting himself, yes, but he would never do it intentionally. And yet, that's what Joseph seems to have done. If one version of his First Vision story involves just an angel and another involves God, the theoretical fraudster-Joseph couldn't have been trying very hard to keep his story straight. It wouldn't have taken very much effort to do so, either! He would have just needed to write the story down somewhere and memorize the details.
Joseph did contradict himself, but deliberately so. I also think that he sometimes lied, using our normal definition for the word. But none of that counted as "lying" to him. Pregnant in Joseph Smith's teachings is a sense of the ineffable. Whether instituting temple ceremonies that must not be outwardly discussed or transcribing Book of Mormon phrases like "that joy which is unspeakable and full of glory" (Helaman 5:44), it's clear Joseph knew that the heart of reality and the divine is beyond the ken of words. Moreover, as his quote "by proving contraries, truth is made manifest" demonstrates, he knew that the ineffable, divine heart of things takes on mutually contradictory forms as it incarnates in the human sphere. In short, I believe that Joseph Smith saw past the game of words we're all normally caught in.
But the trouble is this: when you intimately know the "unspeakable glory" at the heart of reality, how do you communicate it? You can say the words that come to you as you describe that divine reality, but people will ultimately misunderstand your meaning. They will take the words you use (which are necessarily symbolic intermediaries to the ineffable) as the literal truth. Or you can stay silent and keep your visions to yourself, but that helps no one. In truth, I believe that Joseph Smith went another way: since he knew that speakable truth can only ever be a single facet of the inexpressible heart of being, he made it a habit to never get attached to a single version of truth. This has a few consequences. For one (as with paradoxical Zen koans), it trains the mind to think in ways that go "beyond" or "beneath" words. Moreover, it actively dissuades those who are too attached to the "superficial" parts of truth from coming on board with Joseph's spiritual project. Like a parable, only "those with ears to hear" can appreciate the divine life at the heart of Joseph's prophetic career.
I have a few more pieces of evidence for this belief. For one, it resonates with Joseph's strong emphasis on continuing revelation and a never-ending acquisition of truth. A truth that is held too tightly--with too much certainty--is already an idol. "Wo be unto him that saith: We have received, and we need no more!" (2 Nephi 28:27). Moreover, both this and the doctrine of eternal progression implicitly emphasize not only continual progress toward a goal but, as a part of that progression, a necessary continual undoing of outdated truths. To welcome in the new we have to deconstruct the old. As much as Joseph Smith was a revealer of divine truth, he was also a "demolisher" of human truth! He smashed away the human to make way for the divine, and he recognized that we have to do it again and again in order to stop idolatry from crusting over our words.
There is a Jungian archetype for the type of person I have just described: the Trickster. Never "evil," he turns up in cultures all over the world as a playful, rule-breaking anti-hero who goes against convention to reveal the fundamental relativity of all pretension to certainty. Br'er Rabbit is an example of this figure in folklore, as is Anansi, Hermes, or even Charlie Chaplin's "Tramp." Though they seem outwardly foolish and immoral, they conceal a deep inner wisdom and knowledge of the sacred that they never reveal all at once. Joseph does this, as demonstrated above, but I want to make it as clear as I can that this is not a sign of evil or immorality. Just as we need Joseph, we need these figures in our lives. Without the Trickster, we would have gotten stuck to the hardened truths we make into idols long ago. Like Joseph, these Tricksters deconstruct what we're too fond of and, by doing so, open the path to heaven's spacious light once again.