Counterfactual Reasoning in Science

SCHEDULE (times GMT/UTC)

2.30-3.20pm: Ruth Byrne (Trinity College Dublin)
“How people reason with counterfactual andcounterpossible conditionals”

10-min break

3.30-4.20pm: Marco J. Nathan (University of Denver)
“Counterfactuals as Placeholders: Take II”

20-min break

4.40-5.30pm: Peter Tan (Fordham University)
“Two Theses about Modality and Modelling”

ABSTRACTS

Ruth Byrne (Trinity College Dublin)
“How people reason with counterfactual andcounterpossible conditionals”
When people understand and reason from counterfactual conditionals, such as “if the car had run out of petrol it would have stalled”,  they envisage two possibilities, the imagined conjecture (the car ran out of petrol and it stalled) and the presumed facts (the car did not run out of petrol and it did not stall).  Although alternative theories of reasoning have been tested for counterfactuals,  little is known about how people reason with counterpossibles, subjunctive conditionals with impossible antecedents, such as “if lakes were made of bleach people would not swim in them”. I discuss the results of several recent experiments designed to examine how people reason with a range of counterpossibles, that compare those that seem non-vacuously true, to those that seem vacuously true, andthose that seem false. The experiments examine the judgments participants made about whether such counterpossibles are true or false and their tendency to make inferences such as modus ponens and modus tollens. I discuss the implications of the results for theories of how people understand and reason from counterfactual and counterpossible conditionals. 

Marco Nathan (University of Denver)
“Counterfactuals as Placeholders: Take II”
In previous work, I advanced the thesis that counterfactuals, just like their corresponding dispositional properties, are placeholders standing in for predictions or explanations, without themselves actually predicting or explaining anything. This, I maintained, explains the role of subjunctive conditionals and dispositional properties in scientific practice. A few years later, I still believe that both of these constructs are placeholders. However, the placeholder thesis is in need of clarification and amendment. I was wrong to suggest that counterfactuals never explain, and this point can be clearly seen by drawing a distinction between two kinds of placeholders, ‘frames’ and ‘difference-makers.’ The goal of this talk is to elaborate and extend the placeholder view of counterfactuals and its role in scientific explanation, by focusing on examples from various branches of natural and social sciences. 

Peter Tan (Fordham University)
“Two Theses about Modality and Modelling”
Philosophers of science interested in the content of highly idealized scientific representations often claim that their content is modal in nature. There are two prevailing theses about the modal content of idealized models: the view that they provide information about what is merely possible (the “how-possibly thesis”), and the view that their content either literally is or is best understood counterfactually (the “counterfactual interpretation”). These theses about modality and modeling have not received a treatment that compares their advantages, and in fact, only recently has the how-possibly thesis begun to receive more scrutiny. I defend the counterfactual interpretation on three broad grounds. First, it coheres best with broader views about scientific representation; second, it provides a more unificatory account of model formulation and testing; lastly, it best allows for an empiricist-friendly view of the metaphysics of modality.