From the Robin Catalogue:
A. MS., notebook, G-1903-2a, pp. 2-92 (pagination is somewhat irregular but the text is continuous).
Volume I. Published, in part, as 5.590-604 (pp. 28-92). Unpublished: the division of reasoning into deduction, induction, and abduction as deriving from Aristotle and Boole. The relationship of the three kinds of reasoning to the syllogism. A brief review of CSP’s own reflections on the kinds of reasoning, noting articles he published and the errors and confusions these contain.