Ahti-Veikko Pietarinen

New Light on Peirce's Conceptions of Retroduction, Deduction, and Scientific Reasoning

We examine Charles S. Peirces mature views on the logic of science, especially as contained in his later and still mostly unpublished writings (1907–1914). We focus on two main issues. The first concerns Peirces late conception of retroduction. Peirce conceived inquiry as performed in three stages, which correspond to three classes of inferences: abduction or retroduction, deduction, and induction. The question of the logical form of retroduction, of its logical justification, and of its methodology stands out as the three major threads in his later writings. The other issue concerns the second stage of scientific inquiry, deduction. According to Peirces later formulation, deduction is divided not only into two kinds (corollarial and theorematic) but also into two sub-stages: logical analysis and mathematical reasoning, where the latter is either corollarial or theorematic. Save for the inductive stage, which we do not address here, these points cover the essentials of Peirces latest thinking on the logic of science and reasoning.

Exploring the beta quadrant

The theory of existential graphs, which Peirce ultimately divided into four quadrants (

Peirce's Sequent Proofs of Distributivity

upalpha , upbeta , upgamma

The Iconic Moment. Towards a Peircean Theory of Diagrammatic Imagination

α,β,γ and

Let Us Investigate! Dynamic Conjecture-Making as the Formal Logic of Abduction

updelta

Graphical Sequent Calculi for Modal Logics.

δ), is a rich method of analysis in the philosophy of logic. Its