Synthese

Unless one embraces activities as foundational, understanding activities in mechanisms requires an account of the means by which entities in biological mechanisms engage in their activities—an account that does not merely explain activities in terms of more basic entities and activities. Recent biological research on molecular motors (myosin and kinesin) exemplifies such an account, one that explains activities in terms of free energy and constraints. After describing the characteristic “stepping” activities of these molecules and mapping the stages of those steps onto the stages of the motors’ hydrolytic cycles, researchers pieced together from images of the molecules in different hydrolyzation states accounts of how the chemical energy in ATP is transformed in the constrained environments of the motors into the characteristic activities of the motors. We argue that New Mechanism’s standard set of analytic categories—entities (parts), activities (operations), and organization—should be expanded to include constraints and energetics. Not only is such an expansion required descriptively to capture research on molecular motors but, more importantly from a philosophical point of view, it enables a non-regressive account of activities in mechanisms. In other words, this expansion enables a philosophical account of mechanistic explanation that avoids a regress of entities and activities “all the way down.” Rather, mechanistic explanation bottoms out in constraints and energetics.

A new type of formalization of classical first-order logic with equality is introduced on the basis of the sequent calculus. It serves to justify the claim that equality is a logical constant characterised by well-behaved rules satisfying properties usually regarded as essential. The main feature of this approach is the application of sequents built not only from formulae but also from terms. Two variants of sequent calculus are examined, a structural and a logical one. The former is defined in accordance with Dos̆en’s criteria for logical constants. The latter is a standard Gentzen’s sequent calculus and satisfies Hacking’s criteria for logicality, including cut elimination. It is also shown that provided rules are harmonious in the sense advocated by Gratzl and Orlandelli.

How questions are understudied in philosophy and linguistics. They can be answered in very different ways, some of which are poorly understood. Jaworski (Synthese 166:133–155, 2009) identifies several types: (i) ‘manner’, (ii) ‘method, means or mechanism’, (iii) ‘cognitive resolution’, and develops a logic designed to enable us to distinguish among them. Some key questions remain open, however, in particular, whether these distinctions derive from an ambiguity in how, from differences in the logical structure of the question or from contextual underspecification. Arguing from two classes of responses, adverbs and by gerunds, I give the answer that the logical structure of the question is indeed relevant: loosely, manners are adjuncts but methods are arguments.

This article argues against fallibilist evidentialism on the basis of considerations about knowability.