  Erdmann’s discussion of Leibniz can be evaluated as follows. He opened the way for the inclusion of Leibniz’s conception of logic into the actual philosophical debates on logic. This is all the more astonishing as Erdmann was a Hegelian. Hegel was known and heavily criticized for his depreciation of formal logic. On the other hand, stressing the close connection between philosophy and mathematics fits into a time when many philosophers tried to bring philosophy back into contact with the sciences.