Models and Metaphors in Brain Research

Regardless of its seemingly abstract philosophical nature, historically the relation of mind and body has found a surprising variety of forms in the changing “mirror of machines” (Meyer-Drawe, 1996)—perhaps because the “invention” of abstract theorizing and knowledge coincided with the construction of tools and machines. Friedrich Nietzsche brought this articulation of knowledge and machines famously to the fore in his Birth of Tragedy, when he lamented that with the invention of machines, the artful wisdom of the mythos, and the metaphysical consolation it offered, was lost and replaced with the “deus ex machina, namely the god of the machines and crucibles, ... the belief in knowledge and a life led by science” (Nietzsche, 1872, § 17). He dated this shift to the transformation of tragedy from its early to the classical form in Greek antiquity; a period which also saw the rise of science and philosophy. Nietzsche wrote his essay during the Franco–Prussian war, a fact that may have influenced his analysis, because this was a time when modern science and the process of industrialization changed the world in hitherto unanticipated ways (Nietzsche reflected upon this in an introduction of the book which he added later). At the same time, two young physician-scientists once again changed the relation between mind and brain, when they experimented with the application of electric currents to the cortex and observed its excitability. In 1870, Gustav Fritsch and Eduard Hitzig reported on their experiments with cerebrally induced contractions in dogs (Fritsch & Hitzig, 1870; Hagner, 1993). The electric excitability of the brain had been demonstrated almost a hundred years after Luigi Galvani had discovered animal electricity, even though his discovery of it in 1780 had sparked an intense debate on—and much research into—the nature of the nervous principle (Brazier, 1961). Applying electrical stimuli to different sites of the exposed surface of