The word voluntas designated a hermeneutical rather than an anthropological concept in Roman jurisprudence and, we may suspect, sometimes also in general Latin usage. St. Augustine transferred this concept to the field of psychology, thus creating a tool for interpreting and classifying psychological observations
Dihle's central thesis: Augustine did not discover voluntas through introspection but transplanted a juristic hermeneutic into psychology, thereby inventing the concept of will as an autonomous inner faculty.
, The Theory of Will in Classical Antiquity, 1982thesis