My dissertation concerns phenomenal time, i.e. how time appears to us subjectively. The key theme of my dissertation is that thinking about how time appears to us subjectively helps us answer many classic metaphysical questions about the nature of time and human consciousness. Chapter I argues that our mind imposes time upon our consciousness as its essential constitutive structure: in Immanuel Kant’s (1781/1787/1996) language, phenomenal time is an a priori form of our consciousness. I argue that our consciousness is necessarily temporal, and this necessity has an important revelation: our mind does not perceive time, because perception is a causal process, and yet no causal mechanism, due to the contingency of its operation, can ensure that our consciousness is necessarily temporal. Instead I propose that our mind imposes time upon our consciousness as its essential constitutive structure. My proposal leaves open the question of whether the world as it is independent of our conscious experience is temporal at all. Chapter II argues that given how time appears to us subjectively, our consciousness cannot be purely physical. Our immediate present consciousness – what William James (1890/1950) calls the specious present – has a (non-instantaneous) duration. I argue that this specious present is a phenomenally extended unit of consciousness that is mereologically inverted in the sense that the parts depend on the whole: the shorter constituent durations of the specious present cannot exist except as parts of the whole specious present. Yet what is physical – a physical object, process, or functional system – does not have this peculiar property of mereological inversion: instead, any physical whole depends on its parts. Therefore, given such a structural discrepancy, our specious present cannot be identical to, or purely constituted by, what is physical. Chapter III defends the methodology of conscientious introspection employed in the preceding chapters. After clarifying Uriah Kriegel’s (2015) helpful distinction between the reliability and the potency of introspection, I argue that a full appreciation of this distinction has important revelations: one is that many of the pessimistic concerns with introspection threaten not so much the reliability as the potency of introspection; and another is that, once the two notions are disentangled, the reliability of conscientious introspection emerges as eminently defensible.