This project explores the relations between two central themes in contemporary philosophy of language and mind, mental indexicality and phenomenal consciousness, in connection with the mind/body problem. The thesis that there is indexicality at the mental level is the thesis that some thoughts, typically expressible with indexicals like ‘I’ or ‘now’, present the world from a particular perspective in the world. Phenomenal consciousness refers to the subjective quality of our conscious experiences: there is, for instance, ‘something it is like’ to see red. Indexical knowledge (of who and where I am in the world) and phenomenal knowledge (of what it is like to see red) share an important feature: they seem irreducible to objective, third-personal knowledge. But how do the two notions of ‘first-person perspective’ relate exactly? This semantic/epistemic question has metaphysical import in current debates on the mind-body problem, since the apparent gap between the phenomenal and the physical knowledge we have of our conscious experiences is exploited in anti-physicalist arguments. One way to resist the anti-physicalist conclusion is to claim that this epistemic gap has its source not in the nature of consciousness (metaphysical gap), but only in the features of our thoughts about our conscious experiences (epistemic gap). According to a thesis we will call indexicalism, the special features of thoughts about our conscious experiences are indexical features: that is, the epistemic gap is explained via mental indexicality. Given indexicalism, phenomenal knowledge will be reduced to indexical knowledge, which is not usually taken to threaten physicalism. However, indexicalism as it has been developed so far, faces important objections that have led many authors to abandon that theoretical pathway. The project brings together philosophers with complementary expertise on mental indexicality (on the French side) and on phenomenal consciousness (on the Swiss side) to systematically assess two rival hypotheses about so-called phenomenal concepts (concepts we use to think about the phenomenal character of experience). According to the first hypothesis (the Index-hypothesis), an improved understanding of mental indexicality in general will make it possible to elaborate a version of indexicalism about phenomenal concepts which is not vulnerable to the relevant objections. If successful, it protects physicalism about phenomenal consciousness. According to the second hypothesis, phenomenal concepts are no indexical concepts but genuine property concepts which individuate the properties they serve to attribute by the thinker's understanding of what it is to have the relevant property. This claim (the GPC-hypothesis) leads in a natural manner to an anti-physicalist view of phenomenal consciousness. We expect a vivid and fruitful discussion within the project, since the French and the Swiss sides start out with incompatible stances on the two working hypotheses. While important work on both sides in recent years has prepared the ground for elaborating the two working hypotheses, there has been very little direct confrontation of their emerging competing views on the matter. This project is intended to provide the opportunity to do so. Such a confrontation is bound to provide substantial insights into issues that run deep into the origin of the mind-body problem. These insights should contribute crucially to our understanding of ourselves as human beings who are aware of themselves as experiencing subjects with the capacity to reflect on their own conscious states.