An idea posited by this philosopher has been explained by scholars via the “two aspects” and “two worlds” interpretations. In one text, this philosopher argues that certain (15[2])concepts he analyzes are (10[1])objectively valid because experience and apperception are only possible through them. (15[1])This philosopher asserted that morality and freedom are reciprocal through his “reciprocity thesis.” (15[1])This philosopher said (*) space is not an empirical (10[1])concept (10[5])and argued (10[1])we only know (10[1])the world (10[1])through its appearances and not (10[1]-5[1])through (-5[1])the (-5[1])noumenal (10[2])“thing-in-itself.” (10[11])This (10[1])philosopher (10[1]-5[1])argued (10[1])that (-5[1])only maxims that can be (-5[1])willed (10[2])as a universal law (10[4])are (10[1])morally permissible (10[6])through (10[1])a categorical (10[2])imperative (10[6])and, (10[1])in (10[1])one (10[1])book, discussed synthetic a (10[1])priori propositions. (10[1])For 10 points, name this German enlightenment (10[1])philosopher of transcendental idealism and the book Critique of Pure Reason. ■END■ (10[3])