====Important in the second stage====
#Jean Piaget[https://en.wikipedia.org/wiki/Jean_Piaget]#B.L. Whorf[https://en.wikipedia.org/w/index.php?title=Benjamin_Lee_Whorf&redirect=no]#W.V.O.Quine[https://en.wikipedia.org/wiki/Willard_Van_Orman_Quine]#Ludwik Fleck[https://en.wikipedia.org/wiki/Ludwik_Fleck]
#Francis X. Sutton
====Most important ones====
#Charles Morris[https://en.wikipedia.org/wiki/Charles_Morris] #James B Conant[https://en.wikipedia.org/wiki/James_Bryant_Conant]
#Leonard K. Nash
#Stanley Cavell[https://en.wikipedia.org/wiki/Stanley_Cavell]#Paul k. Feyerabend [https://en.wikipedia.org/wiki/Paul_Feyerabend]#Ernest Nagel[https://en.wikipedia.org/wiki/Ernest_Nagel]#hH. Pierre Noyes[https://en.wikipedia.org/wiki/H._Pierre_Noyes]
#John L Heilbron