 Before new sensual and thought forms arise, a certain “specific intellectual unrest must arise and a change of the moods of the thought collective” (1935b). If a person makes an important discovery but social moods do not change, she will not find people who take up her ideas and continue research. On the other hand facts are mutually dependent on each other, so “each new fact harmoniously—though even so slightly—changes all earlier facts” (1935a, IV.3). As a result, it sometimes happens that those initial observations from which a certain research began does not belong to the same class of facts as the one emerging from that research. (The research on the variability of bacteria was initiated by observations made in 1906 by Neisser and Massini, which today are regarded as bacteriophage effects.) Sometimes  nothing remains of the proto-ideas from which investigations started and which inspired early experimental work. (Like the proto-idea of syphilis blood has nothing to do with contemporary Wassermann’s reaction). And finally there arises the edifice of knowledge which was neither intended nor foreseen by anybody.