Epistemic Mediators and Model-Based Discovery in Science

Abstract

What I call theoretical abduction (sentential and model-based) certainly illustrates much of what is important in abductive reasoning, especially the objective of selecting and creating a set of hypotheses that are able to dispense good (preferred) explanations of data, but fails to account for many cases of explanations occurring in science or in everyday reasoning when the exploitation of the environment is crucial. The concept of manipulative abduction is devoted to capture the role of action and of external representations in many interesting situations: action provides otherwise unavailable information that enables the agent to solve problems by starting and performing a suitable abductive process of generation or selection of hypotheses. I will present some aspects of this kind of reasoning derived from the "cognitive" history of the discovery of the non-Euclidean geometries. Geometrical diagrams are considered external representations which play both a mirror role (to externalize rough mental models), and an unveiling role (as gateways to imaginary entities). I describe them as epistemic mediators able to perform various abductive tasks (discovery of new properties or new propositions/hypotheses, provision of suitable sequences of models as able to convincingly verifying theorems, etc.).