I. Philosophy

The term validity was already used by I. Kant (Akademie-Ausgabe IV, 460f.), but it did not play a prominent role in philosophy until the late 19th century. Validity is an actuality, not further explicable, that is understood primarily in contrast to existence. In this sense, R.H. Lotze distinguished between things, which exist, events, which take place, and propositions, which are valid (Grundzüge der Logik und Encyklopädie der Philosophie, 1902; ET: Outlines of Logic an…