In this paper, we propose a decidable single-agent modal logic for reasoning about goal-directed “knowing how”, based on ideas from linguistics, philosophy, modal logic, and automated planning in AI. We first define a modal language to express “I know how to guarantee \ given \” with a semantics based not on standard epistemic models but on labeled transition systems that represent the agent’s knowledge of his own abilities. The semantics is inspired by conformant planning in AI. A sound and complete (...) proof system is given to capture valid reasoning patterns, which highlights the compositional nature of “knowing how”. The logical language is further extended to handle knowing how to achieve a goal while maintaining other conditions. (shrink)

This paper examines whether Sherlock Holmes’ “Science of Deduction and Analysis,” as reconstructed by Hintikka and Hintikka The sign of three: Peirce, Dupin, Holmes, Indiana University Press, Bloomington, 1983), exemplifies a logic of discovery. While the Hintikkas claimed it does, their approach remained largely programmatic, and ultimately unsuccessful. Their reconstruction must thus be expanded, in particular to account for the role of memory in inquiry. Pending this expansion, the Hintikkas’ claim is vindicated. However, a tension between the naturalistic aspirations of (...) their model and the formal apparatus they built it on is identified. The paper concludes on suggestions for easing this tension without losing the normative component of the Hintikkas’ epistemological model. (shrink)

M. B. Hintikka and J. Hintikka claimed that their reconstruction of the ‘Sherlock Holmes sense of deduction’ can “serve as an explication for the link between intelligence and memory”. The claim is vindicated, first for the single-agent case, where the reconstruction captures strategies for accessing the content of a distributed and associative memory; then, for the multi-agent case, where the reconstruction captures strategies for accessing knowledge distributed in a community. Moreover, the reconstruction of the ‘Sherlock Holmes sense of deduction’ allows (...) to conceptualize those strategies as belonging to a continuum of behavioral strategies. (shrink)