Ananya Chattoraj (University of Calgary)
Modal reasoning arises from the use of expressions with modal operators like “necessary” or “possibly.” This type of reasoning arises in science through reasoning about future possibilities. Alethic modal reasoning is instantiated in science through scientific laws and single event probabilities. This means that when scientists use alethic modal reasoning, they appeal to laws and probabilities in their practices of explanation, manipulation, prediction, etc. In the philosophy of logic, alethic modality is sometimes distinguished from epistemic modality under the label of modal dualism (Kment 2014), which is instantiated in science through reasoning about future events based on past experimental results rather than an overarching law. In “An Empiricist’s Guide to Objective Modality,” Jennan Ismael presents a deflationary framework of alethic modality. This framework does not depend on possible worlds semantics and is instead couched in the way in which laws and probabilities guide scientific action. On this account, scientists do not create research programs to falsify theories that have been codified as a law – there is no research, for instance, to falsify gravity, though there are research programs to clarify the nature of the force. As such, laws, and similarly, probabilities, guide the way in which scientists perform their research. The effect of laws as guiding actions, however, has diminishing returns in non-fundamental sciences. In this poster, I present a case study of organic chemistry, where scientists use modal reasoning to classify organic molecules into functional groups. Functional group classification is based on how chemists manipulate molecules of one group by inducing reactions with molecules of a different group for results specific to their purposes. These classifications are experimentally established and provide a systematic way of classifying molecules useful for manipulation, explanation, and prediction. Since these molecules can be classified and named systematically, chemists are reasoning about how molecules will react in future reactions. However, unlike Ismael’s framework suggests, organic chemists are not guided by fundamental laws. Applying works like Goodwin (2013) and Woodward (2014), I show how modal reasoning exists in chemical practice. I argue that alethic reasoning through fundamental laws are downplayed and the non-alethic reasoning is elevated in the practice of organic chemistry. I show that while Ismael’s framework of modal reasoning has features worth preserving, including its abandonment of possible worlds semantics and the focus on action guidance, its focus on alethic modality as the main type of modal reasoning that guides actions is incorrect when considering the practices of scientists working in non-fundamental sciences. I will ultimately suggest that the current way of distinguishing alethic modality and epistemic modality in science is not helpful for understanding modal reasoning in non-fundamental sciences.
