My purpose is to clarify, philosophically, what human persons are. It is our rationality that makes us persons, and I wish to describe such rationality in action, to show how it is made manifest. If I succeed in doing so, I will have helped exhibit what is distinctive about human beings. I will begin, not by making general remarks or offering broad descriptions, but by targeting a particular human activity, something very definite, and using it as a wedge to open up the dimension of being that is proper to persons. The activity I will target is a special way in which we use the word I and its variants, a special way we use the first person, when we speak. Our rationality and hence our personhood come prominently to light in this usage. This phenomenon can then serve – if I may switch metaphors – as a bridgehead for the exploration of other ways in which our rationality appears.