Seybert Commission

The Seybert Commission was a group of faculty members at the University of Pennsylvania who in 1884-1887 investigated a number of respected spiritualist mediums, uncovering fraud or suspected fraud in every case that they examined.

An ardent believer in Spiritualism, Henry Seybert left in his will funds for the establishment of an endowed chair in Philosophy at the University of Pennsylvania. As a condition to this bequest, he required that the University set up a commission to investigate "all systems of Morals, Religion, or Philosophy which assume to represent the Truth, and particularly of Modern Spiritualism." Ten men served on the commission, all of whom declared themselves at the outset to either be neutral or favorably disposed toward Spiritualism. Among the more notable members were the University Provost William Pepper (a physician), the paleontologist Joseph Leidy, the Shakespearean scholar Horace Howard Furness (who served as the chairman), and the physician and writer Silas Weir Mitchell. Also on the commission was George Augustus Koenig, a chemist. A committed Spiritualist and close friend of Henry Seybert, Thomas Hazard, served as counselor, suggesting particular topics and mediums that should be investigated.

The topic most conclusively investigated was "slate writing," in which the medium has two slates fastened together, so that the writing surfaces faced each other, out of reach of the medium, with a small piece of pencil between the two slates. The medium holds the slates in her lap, and spirits purportedly write on the slates, sending the pencil outside the slates when finished. The Commission investigated Mrs. S.E. Patterson and Dr. Henry Slade, both widely respected practitioners of slate writing. Mrs. Patterson proved unable to perform when under the scrutiny of the Commission, while Dr. Slade was found to be practicing fraud: either composing long, well-written messages before the séance, or loosening the screws holding the slates together and scrawling nearly illegible messages while holding the slates in his lap. The Commission also requested that a "professional juggler" attempt slate writing, and found that he was able to provide demonstrations "much more remarkable" than the "puerile" attempts at fraud by Dr. Slade. The Commission concluded that slate writing

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