Realism without tears I: Müller’s Doctrine of Specific Nerve Energies

The Doctrine of Specific Nerve Energies has been and continues to be enormously influential in the physiology, psychology, and philosophy of perception. In simple terms, the Doctrine states that we directly perceive in the first instance the activity of our nerves, rather than properties in the external world. The canonical early statement of the Doctrine by the physiologist Johannes Peter Müller had profound influence on both the philosophy and psychology of the 19^th and early 20^th centuries, especially as reformulated and transmitted by Müller’s student Helmholtz. A common assumption of historical and ongoing debate about the Doctrine has been its supposedly idealist or skeptical implications. What is not commonly recognized is that Müller himself advanced a realist interpretation along lines that would be recognized today as a form of epistemic structural realism. This paper analyzes Müller’s structuralist epistemology in detail and reconstructs his articulation and defense of the Doctrine of Specific Nerve Energies in its canonical form. Part II argues for the continued importance of the Doctrine and its structuralist interpretation for contemporary psychology, philosophy of perception, and history of philosophy of science.     

From Helmholtz to Schlick: The evolution of the sign-theory of perception

Efforts to trace the influence of fin de siècle neo-Kantianism on early 20th Century philosophy of science have led scholars to recognize the powerful influence on Moritz Schlick of Hermann von Helmholtz, the doyen of 19th Century physics and a leader of the zur?ck zu Kant movement. But Michael Friedman thinks that Schlick misunderstood Helmholtz' signature philosophical doctrine, the sign-theory of perception. Indeed, Friedman has argued that Schlick transformed Helmholtz' Kantian view of spatial intuition into an empiricist version of the causal theory of perception. However, it will be argued that, despite the key role the sign-theory played in his epistemology, Schlick thought the Kantianism in Helmholtz' thought was deeply flawed, rendered obsolete by philosophical insights which emerged from recent scientific developments. So even though Schlick embraced the sign-theory, he rejected Helmholtz' ideas about spatial intuition. In fact, like his teacher, Max Planck, Schlick generalized the sign-theory into a form of structural realism. At the same time, Schlick borrowed the method of concept-formation developed by the formalist mathematicians, Moritz Pasch and David Hilbert, and combined it with the conventionalism of Henri Poincaré. Then, to link formally defined concepts with experience, Schlick's introduced his ‘method of coincidences’, similar to the ‘point-coincidences’ featured in Einstein's physics. The result was an original scientific philosophy, which owed much to contemporary scientific thinkers, but little to Kant or Kantianism.