Abstract
Work on 'can' in Action Theory is dichotomized into two styles of analysis: (1) what I call the indeterministic analysis, whereby for x to be able to do A means that there is no obstacle to x's doing A, and (2) the hypothetical analysis, which asserts that x is able to do A if and only if x will do A if x tries (wants, wills, chooses, etc.). This paper explores the general hypothesis that 'can' is two-ways ambiguous, that a sense of opportunity corresponds to (1) and a sense of ability to something after the pattern of (2), and that a general concept of 'can' of the kind often sought after by action theorists requires a certain kind of integration of both concepts into a unified definition. The two previous most well-worked-out attempts to lay out a program along these lines, those of Sellars and Chisholm, are analyzed in detail in the hope of smoothing out some of the technical differences to provide foundations for further work of this type. An attempt is made to integrate the program with some recent developments in the concept of ability in the social sciences. The applicability of this work to some very vexing and significant problems in the social sciences is suggested.