1875 – 1915
Emil Lask (1875–1915) was a German Neo-Kantian philosopher of the Southwest (Baden) School, a student of Heinrich Rickert who pushed value-theoretic Neo-Kantianism into the domain of formal logic and ontology. His major works developed a systematic 'logic of philosophy' and a radically revised theory of categories that sought to overcome the subject-object split inherited from Kant. His thought exercised notable influence on the early Heidegger before Lask was killed in World War I.
Developed a novel categorial theory in 'Die Logik der Philosophie und die Kategorienlehre' (1911), reframing the Kantian categories as forms of validity rather than mental functions
Introduced the concept of 'philosophy of philosophy' (meta-philosophy) as a distinct logical discipline
Advanced the theory of judgment in 'Die Lehre vom Urteil' (1912), influencing subsequent epistemology
Influenced Heidegger's early Freiburg lectures on categories, logic, and the structure of meaning
Extended Southwest Neo-Kantian value theory into a comprehensive theory of theoretical and practical validity