Edgar Cayce (1877–1945)

The sheer volume and specificity of his documented readings, many made while in trance, are hard to dismiss. His medical diagnoses were reportedly accurate enough that physicians took note. He kept meticulous records of over 14,000 readings, making him unusually transparent and even 70 + years after his death, his readings are an open book, subject to inspection and interpretation. It's important to note that some of the "grander" predictions Edgar Cayce made have not come to pass, and some of his historical and archeological claims have come under serious scrutiny, with many being obviously erroneous - over the last few decades as well. That said, his body of work writ large, in particular his preternatural ability to seem to understand the human body, and the ailments of his thousands of visitors over decades of work, while in a clear trance, remain a genuine mystery to beginners, believers and the curious but not convinced.