Columbia subject headings:
Aristotle.
Hartmann, Nicolai, 1882-1950.
Modality (Logic)--History.
Harvard subject headings:
Aristotle--Contributions in logic.
Hartmann, Nicolai, 1882-1950--Logic.
Modality (Logic)--History.
Princeton subject headings:
Aristotle--Logic.
Hartmann, Nicolai, 1882-1950--Logic.
Modality (Logic)--History.