title: Von Neumann was not a Quantum Bayesian.
abstract: Wikipedia has claimed for over 3 years now that John von Neumann was the 'first quantum Bayesian'. In context, this reads as stating that von Neumann inaugurated QBism, the approach to quantum theory promoted by Fuchs, Mermin and Schack. This essay explores how such a claim is, historically speaking, unsupported.
authors.affiliation: Department of Physics, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, MA 02125, USA bstacey@brandeis.edu.
authors.forename: Blake C
authors.identifier: http://orcid.org/0000-0003-2906-1539
authors.initials: BC
authors.lastname: Stacey
keywords: QBism; Quantum Bayesianism; von Neumann