Challenging the Experimentalist Dogma: Empirical Incommensurability in early Neuroscience

In this article we scrutinize what can be called an "experimentalist dogma" presupposed in Pablo Melogno's analysis of empirical incommensurability in the chemical revolution. According to Melogno, the fact that experimental methods were preserved throughout the chemical revolution was an indication that there were no relevant perceptual differences between Joseph Priestley and Antoine Lavoisier. In order to refine Melogno's general analysis, we will present a taxonomy of varieties of empirical incommensurability and discuss their relationships. To exemplify this categorization, and to show its metatheoretical adequacy, we will apply it to the neuronist revolution, that is, to the process of discovery of the neuron in the late 19th and early 20th centuries within neuroanatomy, taking as our main case study the controversy between Camillo Golgi and Santiago Ramón y Cajal. From the analysis of the controversies regarding dendritic spines and stellate cells of the cerebellum, in particular, we question the experimentalist dogma, highlighting how, in these controversies, the conservation of experimental practices does not guarantee the similarity of perceptual contents. Moreover, we will argue that, all other experimental conditions being equal, differences in experiential content between Golgi and Cajal are best explained by differences in their commitments to incompatible conceptual schemes.