One of the easiest ways of testing a theory of consciousness is to apply it to a room full of people — 3 awake adults, for example. If the theory cannot identify (at least) three consciousnesses there is a problem. Yet, almost no proposal to date has the theoretical tools to approach this problem without presupposing brains as the seats of experience (IIT being a notable exception, see also Fekete et al. (2016)). Crucially, causal analysis is the only way to address this individuation problem as I will argue by means of a thought experiment inspired by Searle’s Chinese Room Argument, which I titled “The Greek Cave”. The reason is that identifying conscious individuals in general requires intervening upon the system under study. The implication is that no theory of consciousness can do entirely without assessing causal structure. Any functionalist account that completely lacks reference to causal structure is inadequate, because the same (complex) input-output function can always be distributed across different numbers of consciousnesses.