On Counterfactual Reasoning

Counterfactual reasoning has always played a role in human life. We ask questions like, “Could it have been different?,” “Under which conditions might/would it have been different?,” and “What would have happened if … ?” If we do not find an answer, i.e., what we accept as an answer, we may start reasoning. Reasoning means introducing new information or assumptions, new questions, new answers to new questions, and so on. From a formal point of view, reasoning may be compared with moving stepwise toward a destination in a path system without ever achieving an overview of the system. Seen in this way, reasoning is an activity with its own rationale, which must be studied from the agent’s own perspective. This paper explores the following query: Which conditions are necessarily fulfilled when the act of posing a specific question, or of introducing a particular piece of information or assumption, etc., may count as a step toward the answer to the initial question?