First there is Lehrbuch der Religionswissenschaft (Textbook of the Science of Religion) (1834) in which he bases his religious philosophy on ethics:
Unang doon ay Lehrbuch der Religionswissenschaft (Textbook ng Agham ng Relihiyon) (1834) kung saan siya naka-base sa kanyang relihiyosong pilosopiya sa etika: