Aristotle on the Distribution of Consciousness

Recent discoveries ascribe to some invertebrates (particularly, octopus vulgaris) highly sophisticated cognitive abilities. This triggered a heated debate about consciousness in animals with radically different neuro-structures. In humans, indeed, the thalamocortical complex (T-C) is the necessary structural/anatomical condition for consciousness and cognition. If we could determine that animals lacking the T-C system are conscious, we will have found alien neural organisations carrying out analogous complex cognitive functions. This would break the dogma of the human brain and nervous system as the only sufficient conditions for consciousness; in accordance with the most recent literature in cognitive-neuroscience which is focused mainly on functional properties, e.g. specific neurophysiological processes (such as firing patterns, sleep-wake cycle, firing synchrony, integration of information, etc.), which are present in species with radically different neural architectures, and seem to be crucial for consciousness in humans and higher mammals. I argue that this possibility is compatible with Aristotle’s theory of soul by proposing an interpretation of the controversial soul-boatman analogy at De Anima 2.1. 413a 8-9. A correct interpretation of the analogy shows how, within a hylomorphic framework, the possibility of a distribution of consciousness alongside the phylogenetic tree has been open by Aristotle, thousands of years ago.