He resigned from this position in 1781, after which he prepared his university lectures for publication in two books: Essays on the Intellectual Powers of Man (1785) and Essays on the Active Powers of the Human Mind (1788).
Ta astus sellelt ametilt tagasi 1781. aastal ning vormistas oma ülikooli loengud avaldamiseks kahes raamatus: „Essays on the Intellectual Powers of Man“ (1785) ja „Essays on the Active Powers of the Human Mind“ (1788).