Columbia subject headings:
Islamic philosophy--Early works to 1800.
Philosophy, Arab--Early works to 1800.
Soul--Islam--Early works to 1800.
Harvard subject headings:
Ikhwān al-Ṣafāʼ
Ikhwān al-Ṣafāʼ. Rasa'il.
Islamic philosophy--Early works to 1800
Philosophy, Arab--Early works to 1800.
Soul--Islam--Early works to 1800.
Princeton subject headings: