"I enter a new planet, everything is transformed, a sublime sight." This impression and enthusiasm accompany Bonstetten in his philosophical work between the ages of 60 and 87. The present volume brings together the writings he published during this period - the "Recherches sur l'Imagination" (Geneva, 1807), the "Études de l'homme" (Geneva, 1821), the "Philosophie der Erfahrung" (1828), and the "Essais" in the Bibliothèque Universelle - along with a large number of rediscovered manuscripts, which can broadly be referred to as philosophical diaries. This restores Bonstetten's meditations to their inherent fluidity of provisionality. On the horizon of his thought appear Aristotle and Cicero, Bacon and Leibniz, Charles Bonnet, whom he studied with in the 1760s, the Scottish school, Smith, Hume, Stewart, the Kr.