Causality and irreversibility in health phenomena: The notion of semelfactivity

This paper aims at pointing a particular aspect of the temporality of health, namely the “semelfactivity” (characteristic of what happens only once) of the phenomena that are connected to it. This semelfactivity, which contributes to giving an irreversibility to the temporality of health, stems from the fact that the health phenomena are part of causality networks which are intrinsically entangled. It compels, thus, to set anew, from a more general philosophical point of view, the question of the relationship between causality and irreversibility.