Leibowitz and Agassi: Conversations on Philosophy of Science - Part 13

The thirteenth installment in the celebrated series of dialogues between Professor Yeshayahu Leibowitz and Professor Joseph Agassi focuses on what is arguably a cornerstone of modern philosophy of science: the boundary between science and metaphysics, and the subsequent question of the nature and validity of scientific knowledge. This debate strikes at the very heart of the human essence and worldview, reflecting the turbulent intellectual clashes of the twentieth century regarding the role and centrality of science in society. The discussion likely centers on the impact of the "Copernican Revolution" in the philosophy of science, primarily associated with Karl Popper and Thomas Kuhn—two thinkers at the core of the era's scientific-philosophical discourse. As a prominent student of Karl Popper, Professor Agassi faithfully represents the Popperian stance, which views "falsification" as the central touchstone and distinguishing criterion between a scientific theory and a non-scientific claim. For Popper—and by extension, Agassi—science is not built upon repeated verifications, but rather on the willingness of theories to be tested and potentially refuted. A theory that cannot be falsified, for any reason, is not a scientific theory, but remains at best metaphysics or pseudo-science. This approach, which emphasizes constant criticism and the pursuit of refutation, stands in stark contrast to classical inductive methods where science progresses by accumulating observations and formulating general laws. Thinkers like David Hume, who exposed the problem of induction back in the 18th century, provided the philosophical groundwork for this critique, which reached its zenith in Popperian philosophy. Isaac Newton, of course, serves as the paragon of classical scientific theory, justifying itself through countless successes interpreted as induction. However, the emergence of Albert Einstein, with a General Relativity that shattered the foundations of Newtonian physics, reinforced the notion that even the most successful theories are provisional and subject to change. Ernst Mach, with his radical opposition to metaphysics and concepts that cannot be directly observed, also serves as an important background figure representing a strict empiricist view. Conversely, Leibowitz, from his distinctly anti-metaphysical position, joins the critique of totalitarian scientific views but from a slightly different perspective. Leibowitz does not view science as a mission to uncover some "absolute truth" inherent in nature, but rather as a pragmatic human activity that serves human needs, allowing man to control his environment and predict phenomena. For him, science holds no inherent moral or metaphysical standing; its role is to describe "what is" rather than "what ought to be." This sharp separation between fact and value, and between science and other realms of the human spirit (such as religion, ethics, and art), is a cornerstone of his thought. Leibowitz views the very attempt to attribute metaphysical truth or essential existence to science beyond human activity as the beginning of a dangerous distortion—one that transforms science into a new idol. This conversation undoubtedly explores the tension between "science as a method"—a formal mechanism of thought and experiment—and "science as knowledge"—an accumulated body of understandings about the world. The central tension expected to emerge in this segment arises from the attempt to define the very nature of science: is it a dry, value-neutral mechanism for prediction and control, as Leibowitz suggests, or does it offer a deeper avenue for knowledge of the world, even if that knowledge is never final, as Agassi argues under Popper’s influence? Does Agassi’s position, which emphasizes falsification, create an internal "value" system within science (the value of criticism, for example), and if so, how does it align with the sharp Leibowitzian separation? There will likely also be tension surrounding the question of "reality"—do scientific theories describe an objective reality, or are they merely effective tools for navigating the world? Should the name of Émile Durkheim arise, it would likely be in the context of sociological perceptions of science, viewing it as a social institution rather than merely a private intellectual act. The series "Leibowitz and Agassi: Conversations on the Philosophy of Science" remains a cultural and educational document of the highest importance in Israel to this day. Beyond its profound philosophical content, it demonstrates a meticulous, serious, and respectful intellectual debate, even when opinions are diametrically opposed. It offers a rare glimpse into the worlds of two intellectual giants who dominated the Israeli cultural stage, presenting complex philosophical issues to the public in clear, rich language, punctuated by sharp examples and extraordinary mental acuity. The series serves as a beacon of rationality and critical thinking, encouraging independent and deep reflection on the foundations of human knowledge in general, and science in particular—topics whose relevance only grows in modern society. It teaches that a substantive and profound dialogue can be maintained even when starting points are fundamentally different, serving as an instructive lesson in intellectual democracy.

Video transcript