Meiers big ›Vernunftlehre‹ (Doctrine of Reason) is not a random source used by Kant in addition to numerous others. In fact it appears that Kant used Meier‹s big work as a compendium for his lectures to begin with and then switched over to Meier's ›Auszug aus der Vernunftlehre‹ (Excerpts from the Doctrine of Reason) after a few semesters. When he switched, he wrote down numerous excerpts from the big ›Doctrine of Reason‹ in his personal interleaved copy of this compendium, as Erich Adickes demonstrated. In her study of ›Kants Logikvorlesungen als neuen Schlüssel zur Architektonik der Kritik der reinen Vernunft‹ (FMDA I,9) (Kant's Lectures on Logic as a New Key to the Architectonics of the Critique of Pure Reason), Elfriede Conrad listed these meticulously. Thus this volume is an important supplement to the index volumes previously published concerning his works on logic. It shows precisely how Meier's big ›Doctrine of Reason‹ left a lasting mark on Kant's thinking.