Sometime in December 1840, JS delivered a discourse on a method for discerning types of spirits and angels. Little information is known about this discourse. The only known account is the one featured here, inscribed by L. John Nuttall in the opening pages of his 1880 notebook. He copied the sermon—along with other discourses—from a source he called “’s Private Book.” Clayton arrived in at the end of November 1840, and he may have recorded his account around the time JS gave the discourse. To what extent Nuttall accurately or comprehensively captured Clayton’s earlier notes of this discourse is unclear. The surviving text does not indicate whom JS addressed, when in December he delivered the sermon, or how long he spoke. However, the reported content of the discourse matched instructions that JS gave repeatedly during the final years of his life. On 27 June 1839, he taught the about the same key to discerning good versus evil spirits and repeated the instruction almost verbatim to a small gathering on 9 February 1843.