The need to take the spiritual experience during illness into account is part of a broader trend in Western societies--a fascination with the practical uses of spirituality and its contribution to individual wellbeing, whether through a religious or a humanist tradition. This understanding of spirituality differs from traditional views embedded in religious traditions. This book takes a critical point of view at the biomedical representation of the function of spirituality in care. Medicine reorders notions such as life, death, health, sickness, and spirituality. This process is called here "sapientialization", i.e. the spiritual experience is expressed and understood under the auspices of and in terms of wisdom. This view tends to identify spirituality and ethics. I propose an alternate understanding of spirituality, grounded on its subversive power. Inspired by the work of the theologian John D. Caputo, it is critical of some problems that are associated with the sapientialization of spirituality in biomedicine, such as the medicalization of spiritual experiences or the instrumentalization of spirituality. It provides an understanding of spirituality that honours both the medical interest in it and its capacity to resist to instrumentalization.