Abstract
This dissertation explores the possibility of phenomenal consciousness in functionally and spatially distributed systems and investigates the grounds of phenomenal consciousness in such systems. My aims are to explain how consciousness arises in a variety of distributed systems and to contribute to discussions on what is required for consciousness and what kind of systems are conscious. I first challenge the standard view that consciousness of a distributed system will be (necessarily) disunified. I offer a novel externalist account of phenomenal unity which uniquely explains how phenomenal unity and disunity are realized in split-brain subjects. I then offer an explanatory model of consciousness which illustrates how synchronic unity of consciousness can be realized in octopuses despite their broadly distributed nervous systems. This model suggests that octopuses have multiple experiences sequentially rather than simultaneously. Furthermore, I argue if octopuses have multiple experiences simultaneously, then the most plausible view is that consciousness of an octopus is unified at least to an extent. Finally, I focus on forests and establish that the most plausible claim about massively distributed systems which have complex integration among their parts and rich recurrent processes is that they are conscious.