BackgroundMotivation is a crucial and widespread theme within medicine. From clinical to surgical scenarios, acquiescence in taking a pill or coming to a consultation is imperative for medical treatment to thrive. The “decade of the brain” gave practitioners substantial neuroscientific data on human behavior, helped to explain why people do what they do and created the concept of “motivated brain”. Findings from empirical psychology stratified motivation into stages of change, which became more complex over the decades. This research seeks to improve the understanding of how people make decisions about their health, and how to better understand strategies and techniques to help them resolve ambivalence in an effective goal-oriented way.MethodsWe establish a dialogue with Ricoeur’s phenomenology of the will in order to understand the meaning of these scientific findings. Starting from Husserlian phenomenology, Paul Ricoeur developed his thoughts away from transcendental idealism, through emancipating the intentional structures of the will from the realm of perception.ResultsThrough introducing the concepts of the voluntary and the involuntary, Ricoeur deviated from Cartesian dualism, which renders the body as an object body, a target of natural vicissitudes. The new dualism of the voluntary and the involuntary is dealt with by reference to what Ricoeur called the central mystery of incarnate existence, which considers man “double in humanity, simple in vitality”. This duality makes it possible to consider the brain to be the natural organ of behavior in the human body, and to use empirical psychology as a path to escape from shallow subjectivations of concepts.ConclusionsPaul Ricoeur’s simplicity (or unity) of existence provides an invitation for medicine to rethink some of its philosophical assumptions, such that patients can be considered to be autonomous subjects with authorial life projects. Ricoeurian anthropology has a deep ethical impact on how medicine should use technology, which arises from empirical psychology findings. The usage of this new knowledge also needs to be thoroughly inspected, since it shifts the social role of medical science.