Leibowitz and Agassi: Conversations on Philosophy of Science - Part 1

The opening session of the classic Panorama series "Leibowitz and Agassi: Conversations on the Philosophy of Science" serves as a riveting and profound introduction to the world of scientific inquiry. Against the backdrop of public television, two giants of Israeli thought confront one another: Professor Yeshayahu Leibowitz and Professor Joseph Agassi. The first part of this dialogue is dedicated to the fundamental question: What is science? More precisely, it is an attempt to map the boundaries and essence of scientific knowledge, touching upon the very heart of the philosophy of science: how we distinguish between a scientific claim and a non-scientific one, and the mechanisms by which scientific progress occurs. The discussion is anchored in the major 20th-century currents of the field, bringing to the surface the approaches developed by Karl Popper and Thomas Kuhn, alongside echoes of earlier insights from thinkers like David Hume. At the center of the debate lies Karl Popper’s Principle of Falsification, for which Agassi, as his preeminent student, serves as a passionate advocate. Unlike many of his predecessors, Popper viewed induction—the drawing of general conclusions from specific observations—as a fundamental flaw in the scientific method and a danger that establishes a false sense of certainty. In its place, Popper proposed falsification: a scientific theory is not tested by the infinite accumulation of supporting observations, but rather by its vulnerability to being proven wrong by a single contradictory observation. Thus, science is not a collection of truths, but a continuous process of formulating bold hypotheses and testing their resilience against attempts to refute them. Popper’s ideas, inspired by Einstein’s Theory of Relativity (which he saw as the ultimate example of a falsifiable theory), stand in sharp contrast to earlier inductive approaches that reached an impasse with David Hume, who exposed the "problem of induction" and our inability to derive certain knowledge from it. Leibowitz, for his part, while not a strict Popperian, shares many of the critiques directed at inductive schools of thought. Leibowitz is a distinctly anti-metaphysical philosopher; he rejects any attempt to attribute ontological or metaphysical "Truth" to science. To him, science does not reveal "things as they truly are," but is rather a human activity—a practical tool for organizing knowledge, making predictions, and mastering the world. In Leibowitz’s view, science operates strictly within the boundaries of empirical description, and he maintains a sharp, unbridgeable divide between "facts" and "values." Science can describe the world and show us "how things work," but it possesses no authority to settle questions of "what is worthy" or "what is ethically right." This perspective aligns closely, in some respects, with the Popperian critique of scientific certainty, leading to the conclusion that the essence of science is not "discovering truth," but constructing effective models and tools. The central tension of the conversation stems from their attempt to define scientific activity and locate it within the spectrum of human knowledge. Agassi, in his Popperianism, emphasizes relentless self-criticism and falsification as the heart of science. For him, scientific progress is not the random validation of theories, but the constant attempt to debunk them and formulate new, bolder theories that are empirically testable and offer better explanations for phenomena. Leibowitz likely responds by agreeing with the necessity of criticism, yet qualifying any attempt to grant science a status beyond practical human activity. He emphasizes that science, regardless of its apparent progress, lacks the power to transcend the "how" and touch upon the "why" or the "meaning." Consequently, the questions of "what is science" and "how it advances" transform into essential inquiries regarding man’s place in the universe and the inevitable limits of human intellect. The discussion also touches upon other thinkers, such as Thomas Kuhn, whose seminal work "The Structure of Scientific Revolutions" shook the scientific world. Unlike Popper, Kuhn emphasized the importance of "paradigms"—the theoretical frameworks and worldviews accepted by the scientific community. He argued that science does not progress through linear refutation, but through "scientific revolutions"—fundamental shifts from one paradigm to another involving radical changes in worldview, the questions being asked, and research methods. Agassi may present Popper’s attempts to answer Kuhn's critique, while Leibowitz might view these revolutions as existential shifts in human activity—changes in how man grapples with reality that do not necessarily reveal a "deeper truth." This first part of the dialogue is not merely a lesson in the philosophy of science; it is a vital cultural document reflecting the intellectual spirit of its time in Israel. These two thinkers, of immense academic and public stature, conduct a deep yet accessible conversation that reveals the depths of critical thought to a broad audience. The dynamic between them—the clear and systematic Agassi, the disciple of Popper, and the brilliant, occasionally cynical, but always profound Leibowitz—creates a captivating intellectual experience. These talks provided the Israeli public, and generations of students, with an unmediated encounter with complex philosophical ideas, offering tools for the critical analysis of knowledge and the world. It is a rare record of profound philosophical thinking delivered through mass media, leaving an indelible mark on Israel's intellectual discourse. The educational and cultural significance of this exchange, and the series as a whole, remains beyond doubt.

Video transcript