Zweierlei Denken: Ein Beitrag zur Physiologie des Denkens

In this early‑20th‑century lecture a pioneering mind turns the fledgling science of physiological psychology toward a fundamental question: how do the brain’s physical processes give rise to two distinct modes of thought? The speaker distinguishes “imaginal” thinking, rooted in vivid sensory representations, from “conceptual” thinking, which abstracts and categorises those images into logical structures. By framing the discussion within the measurable realm of nerve‑cell energy flow, the talk seeks a concrete footing for ideas that were still controversial among neurologists and anatomists of the day.

The argument proceeds from the simplest neural event—the reflex—to the complex, centrally coordinated reactions that incorporate past experiences. The author proposes that all mental activity can be understood as the propagation and regeneration of chemical signals along neural pathways, moving at roughly thirty metres per second. This physiological view treats thought as a cascade of measurable, causal processes rather than an unapproachable mystery.

For listeners today, the lecture offers a rare glimpse into the early attempts to bridge biology and cognition. It reveals how the debate over “dualism” versus a unified naturalistic account of the mind was already shaping experimental approaches, making the work a valuable historical touchstone for anyone interested in the roots of modern cognitive neuroscience.