Perspectives on clinical possibility: Elements of analysis

Possibility is one of the most common modalities in reasoning and argumentation. Various kinds of modal concepts have been identified in philosophical and logical discussion of the metaphysics of modality. We focus here on the concept of clinical possibility. A critical analysis of what is intended as clinical possibility has not yet received sufficient examination, although the concept is extensively used in clinical reasoning. We present arguments toemphasize some desirable features associated with the conceptof clinical possibility. We argue that almost all clinical possibilities are potentialities, that is, possibilities that may be actualized by effective, appropriate and feasible interventions. However, in some limited cases, even mere possibilities – which may or may not be actualized, since we do not have the required knowledge – may be involved in clinical reasoning, and we present some examples in this paper. We then introduce some basic views on the nature of possibility showing their validity and limitations when applied to the concept of clinical possibility. Lastly,weconjecturethatclinicalpossibilityisanormativemodalitythatcanbeformalized in a multimodal system with epistemic and deontic logical operators.