In what follows I shall speak about many phenomena, but what I wish to convey more than anything else is a combination of positive aspects of the rightly famous seminar headed by Moritz Schlick the years before he was shot on the stairs of the University of Vienna in 1936. These aspects make the seminar unique. I have taken part in a wealth of good seminars before and after 1936, but my experience as a participant of that seminar makes it, for me, stand out as unsurpassed.