My research focuses on the notion of self-consciousness. Various authors – philosophers and scientists alike – have argued that self-consciousness is essential for consciousness in general. On a strong reading of this claim, a given subject (e.g. a human being) is necessarily self-conscious whenever they are conscious at all. My doctoral project seeks to examine and assess this claim. The first step is to disambiguate the meaning of “self-consciousness”. I distinguish two broad meanings of the term that have been occasionally conflated in the literature, namely “consciousness of consciousness itself” and “consciousness of oneself”. I subsequently examine each of the resulting claims, in the first and second parts of my thesis respectively.

The idea that self-consciousness, understood as “consciousness of consciousness”, may be necessary for consciousness in general finds expression in the following hypothesis: a subject’s mental state is conscious if and only if the subject is conscious of it. On the basis of conceptual grounds and empirical results from psychology, I argue against an inflationary construal of this hypothesis, according to which whenever I am in a conscious mental state (e.g. seeing a blue sky), I am not only aware of the ‘external’ object of that mental state (the blue sky itself), but also of the mental state itself (my visual experience of the blue sky) in such a way that my inner awareness of my mental state makes a contribution to my overall experience. I conclude that self-consciousness, understood as “consciousness of consciousness” in the sense outlined above, is not necessary for consciousness in general.

In the second part of my thesis, I turn to the idea that consciousness of oneself is necessary for consciousness in general. Thinking about oneself is an obvious way to be conscious of oneself, but it is clearly not necessary for consciousness as we are not constantly thinking about ourselves in our waking life. Being aware of one’s body and of one’s location in space are arguably also forms of self-consciousness. On the basis of empirical evidence from the study of certain altered states of consciousness (specifically states induced by certain forms of meditation, psychoactive drugs or sensory deprivation), I argue that bodily awareness and self-location are not necessary for consciousness either, as they can go missing in these states. However, I argue for a weaker claim according to which spatial self-location is a form of self-consciousness that is ubiquitous in ordinary experience, while bodily self-consciousness is pervasive (but not entirely ubiquitous) in ordinary experience.