A “_person_” is simply a _subsisting_ nature that is _rational_, _intelligent_: _Persona est suppositum rationale_. The definition given by Boëtius is classic: “_Persona est substantia individua_ RATIONALIS _naturae_”: “the individual substance of a rational nature,”—where the term _individual_ is understood to imply _actually existing and subsisting_. The special name which has thus been traditionally applied to _rational_ or _intelligent_ subsisting beings (as distinct from animals, plants, and material “things”)—the term “person” (“_persona_,” a mask: _per-sonus_; _cf._ Gr. προσωπέιον, from προσώπον, the face, countenance)—originally meaning a rôle or character in a drama, came to be applied to the subsisting human individual, and to connote a certain dignity of the latter as compared with the lower or non-rational beings of the universe. And in fact the ascription of its actions to the subsisting being is more deeply grounded in the subsistence of rational, intelligent beings, who, as free agents, can more properly direct and control these actions.(291) 73. DISTINCTION BETWEEN THE INDIVIDUAL NATURE AND ITS SUBSISTENCE. WHAT CONSTITUTES PERSONALITY?—Knowing now what we mean by the terms “subsistence,” “suppositum,” “person,” and “personality,” we have next to inquire in what precisely does subsistence consist. What is it that constitutes a complete individual nature a “subsisting being,” or if the nature be rational, a “person”? Subsistence connotes, over and above the mode of “existing in itself” which characterizes all substance, the notion that the substance or nature is individual, that it is complete, that it is in every way incommunicable, that it is _sui juris_ or autonomous in its existence and activities. These notions are all positive; they imply positive perfections: even incommunicability is really a positive perfection though the term is negative. But is any one of the positive perfections, thus contained in the notion of subsistence, a positive something _over and above_, and _really distinct from_, the perfection already implied in the concept of _a complete individual nature as such_? Some of those philosophers who regard the distinction between essence and existence in creatures as a real distinction, identify the _subsistence_ of the complete individual nature with its _actual existence_, thus placing a real distinction between nature and subsistence or personality.(292) Apart from these, however, it is not likely that any philosophers, guided by the light of reason alone, would ever have held, or even suspected, that the subsistence of an actually existing individual nature is a positive perfection really distinct from, and superadded to, the latter. For we never, in our natural experience, encounter an existing individual substance, or nature, or agent, that is not distinct, autonomous, independent, _sui juris_, and incommunicable in its mode of being and acting.