The Epistemology of Microphysics

Edward Feser's lecture, "The Epistemology of Microphysics," delivered at the American Maritain Association, delves into the philosophical underpinnings of how we understand the subatomic world. He addresses the remarkable success of microphysics in uncovering unseen realities, alongside its recent slowdown, which some critics attribute to an over-reliance on untestable mathematical constructs. Feser proposes that Thomistic philosophy can illuminate both the achievements and current frustrations in this field.

• Historical Progression: The story traces the development of atomic theory from ancient Greek atomists to the Standard Model, highlighting the evolution from speculative ideas to experimentally verified particles like electrons, protons, and quarks. It emphasizes how increasingly sophisticated experimental apparatus (cloud chambers, colliders) and theoretical inferences ("inference to the best explanation") were crucial for these discoveries.
• Abstraction and Mathematics: Over time, particles became less "picturable" and more abstract, with mathematical descriptions superseding intuitive physical models. Figures like Norwood Russell Hanson are cited to explain how properties like color or even determinate position and velocity were stripped away, leaving highly abstract, mathematically defined entities.
• Models and Analogies: Mary Hesse's work on models and analogies is introduced, explaining how scientific concepts often begin with familiar analogies (e.g., gases as billiard balls) that are refined through positive, negative, and neutral analogies as understanding deepens.
• Thomistic Insights (Maritain): Jacques Maritain's Thomistic perspective parallels Hanson's, viewing microphysical entities as "symbolically reconstructed real beings" or "mathematically conceived entities." Maritain differentiates between the certitude of a particle's existence and the less certain, mathematical nature attributed to it.
• The Triplex Via Parallel: Feser draws a novel parallel between the Thomistic "triplex via" (ways of knowing God: causality, negation, eminence) and the epistemology of microphysics. Just as our knowledge of God starts from effects, denies limitations, and infers perfections, microphysics reasons from observed phenomena, denies ordinary properties to particles, and deduces their natures based on their potentiality to constitute all matter.
• Limits of Knowledge: He argues that just as our intellect's grasp weakens when approaching the divine (pure actuality) or prime matter (pure potentiality), so too does physics' ability to establish firm knowledge as it delves deeper into the microstructure. This explains the "marginalization of phenomena" in recent microphysics, where the link between empirical evidence and theoretical entities has become increasingly distant.
• Critique of Aestheticism: Feser criticizes the reliance on aesthetic considerations (beauty, elegance) in theories like string theory, echoing critics like Sabine Hossenfelder. While beauty is a transcendental, it cannot reliably lead to truth without empirical verification, similar to how one cannot reliably deduce God's existence solely from the idea of His perfection.

In conclusion, Feser, through a Thomistic lens, asserts that current theoretical physics, particularly string theory, has strayed by prioritizing mathematical aesthetics over empirical testability. He advocates for a return to the traditional scientific method, emphasizing experimental verification, and suggests that physics must accept inherent limits to its inquiry, just as natural theology does when contemplating the divine.