From the Robin Catalogue:
A. MS., G-1893-5, pp. 31-46 (pp. 34, 42 missing).
Published, in part, as 2.281 (pp. 35-36), 2.285 (p. 41), 2.297-302 (pp. 43-45). Unpublished: reasoning as an interpretation of signs of some kind; the three different states of mind feeling, reacting, thinking (pp. 31-34). Indices and icons (pp. 37-40). Reasoning as requiring a mixture of likenesses, indices, and symbols (p. 46).
Published as “What Is a Sign?” EP 2:4-10.