This book begins by drawing attention to the fact that many people acknowledge having had a transcendent experience, namely an event in which they had the impression that they were in contact with something boundless and limitless, which they could not get hold of, and which utterly surpassed human capacities. Prompted by such sociological data, the author endeavours rigorously to show that the human person is open to the infinite. Since transcendent experiences involve an emotional response and an intelligible discovery, he explores both the affective and intellectual sides of this openness and their interrelation. The first part is phenomenological; the second, a history of great ideas; and the third, philosophy of religion. Part One offers an original account of types and elements of transcendent experiences. It also analyses four narratives. Part Two introduces some of the major classical thinkers of modernity: Kant, Schleiermacher, Hegel, James and Otto, as well as more recent ones such as MarTchal, Rahner, and Lonergan. In this part, there is a fresh reading of these authors' reflections on the human being and the infinite. Part Three makes a contribution to current issues such as experience and interpretation, intentionality and transcendence, the relationship between the infinite and the indefiniteness of the imagination and of reason, directness and mediation, and the role of feelings in religious experience. The author concludes that the human person is open to an infinite that is real and yet unknown by the human intellect.