1 The Extension of Senses Babu Thaliath Senior Fellow, Zukunftskolleg University of Konstanz babu.thaliath@uni-konstanz.de Orcid code: https://orcid.org/0000-0002-4557-7765 Abstract The extension of senses remained an unresolved aporia throughout the history of the theory of perception. An appropriate example of the historical persistence of this aporia would be the priority-dispute between extramission and intromission theories of vision prevailing since the ancient philosophy of Plato, Aristotle, Plotinus and others. The resurgence or rehabilitation of the intromission theory of vision in the early Cartesian modernity strategically reversed the predominant position of the sense of touch – over all other senses – in favor of the sense of sight, which had prevailed until the end of Middle Ages. Since then, the external extension of vision has remained an aporia, as problematized and discussed in the works of Descartes, Locke, Molyneux, Berkeley, Condillac, Diderot, Helmholtz, Gibson, and others. The present treatise is an attempt to reconsider the aporicity of the bodily and extra-bodily extension of senses and resolve it by means of a methodological analogy between the bodily extension of sensibility and the extra- bodily extension of the senses of sight and hearing. The focus is on the extra-bodily extension of the sense of sight, which, thanks to the unsettled legitimacy-dispute between intromission and extramission theories of vision, has come to the fore as the most important aporia of sensibility. On the theoretical level, this investigation tries to overcome the unfortunate divergence between philosophical and scientific epistemology and thus to regard them as complementary to one another. This should result in a scientific proof, in which the real extension of the bodily and extra-bodily senses is dictated by a philosophical epistemology and confirmed by a scientific- experimental investigation. The complementarity of philosophical and scientific theories of perception The bodily and extra-bodily extension of senses refers to completely different modes of existence, namely the mind and the body. Since the emergence of the Cartesian modern age, sensory perceptions as fundamental epistemological processes were generally ascribed to the perceiving subject; on the other hand, the connectivity of the senses with the body and the external extension of the sense of sight and hearing tend to be regarded by philosophy as aporias. The complete separation of subjective sensation from the object – an undertaking which is decisive and propaedeutic for modern epistemology – was hardly strived for in the traditional scholastic philosophy. 1 On the other hand, the complete separation of the sensory qualities from the object of perception and their appropriation by the perceiving subject, which Descartes achieved through his method of doubt and negation, became a propaedeutic to modern epistemology in general. Cartesian dualism, as most closely represented in its