The meaning of a proposition is the method of its verification.

In 1904 he completed his dissertation essay "Über die Reflexion des Lichts in einer inhomogenen Schicht" ("On the Reflection of Light in a Non-Homogeneous Medium"). Schlick ( [Wende] p. Schlick and his group were impressed by the work devoting considerable time to its study and even when it was no longer the principal focus of their discussion it was mentioned in discussion.

Friedrich Albert Moritz Schlick (German: [ʃlɪk] ([Image] listen); April 14 1882 – June 22 1936) was a German philosopher physicist and the founding father of logical positivism and the Vienna Circle.