Beyond Popper and Polanyi: Leonor Michaelis, a Critical and Passionate Pioneer of Research at the Interface of Medicine, Enzymology, and Physical Chemistry

The biochemist and biophysicist Leonor Michaelis (1875-1949) was a renowned pioneer who worked at the interface of physical chemistry and biochemistry. He is best known for his work on the physical chemistry of proteins and enzymes and for the mathematical derivation, together with Maud Menten, of the affinity constant of the enzyme substrate bond, now known as the Michaelis-Menten constant. His thorough experimentation and careful theorizing made him critical of his contemporaries in medical biochemistry, whose work did not withstand scrutiny. His strong influence resulted from combining new concepts and approaches with traditional ones, thus bridging conceptual gaps. Most importantly, his success was brought about because he combined a critical and sharp mind with competence, passion, and determination. A review of Michaelis's approach and achievements shows that critical theory testing, as suggested by Popper, cannot explain scientific advance if taken alone; the existence of a passionate commitment to scientific beliefs, as emphasized by Polanyi, is another necessary prerequisite for the development of science.