  The Trinitological concept of the person was far from the modern meaning that the term assumes in personalism, and Boethius’ definition too indicates only in the barest abstract outline the deep and comprehensive signification that personalism ascribes to it. As accepted by personalism, it is the result of a long and complex cumulative development, resulting in a rich, if somewhat elusive, concept which in some respects wholly inverts the original connotations of exteriority in the early meanings of “mask” and “role”: person comes rather to denote the innermost spiritual and most authentic kernel of the unique individual, while retaining a radical openness to the external. Already in the course of the Middle Ages, further definitions were provided, and not just by Aquinas. Not least the Augustinian example of experienced interiority and reflexivity, the idea of form as the principle of individuation, and the late medieval and Franciscan emphasis on will and singularity entered into early modern thinking about the person, and combined with the stronger focus on human personality that was characteristic of Renaissance humanism.