In the present study, an attempt was made to examine the theoretical basis of the mind-body relationship in the context of physical education. The discussion centred on the mind-body theory of Rene Descartes (1596-1650) and the theory of “Dualicisme,” which are well known in the extant literature. In the field of physical education philosophy, the mind-body relationship continues to draw interest, but to date there is no common academic consensus among researchers. Accordingly, it seems informative to examine the fundamental mind-body relationship from the philosophical perspective of Descartes. According to Descartes, the ontological state of mind and body is “substantial union,” which considers the substance of both mind and body and unites them closely. The interaction between mind and body, on the other hand, is understood according to the “primitive notions” as “the union of mind and body.” Only this idea of “the union of mind and body” can be retained, it allows a full appreciation of the nature of physical education, and a better understanding of the mind-body relationship. Consideration should also be focused on Descartes himself, who has long been misunderstood in the philosophy of physical education, and more enlightened discussion can ensue by elaborating on his mind-body theory.