Using terminology from linguistics, we can distinguish activities of two fundamental kinds. Telic activities — from “telos,” the Greek word for purpose — aim at terminal states, by which they are completed. Think of reading this article or driving home from work. Once you arrive at the goal, you are finished: The point of the activity has been achieved. You can do it again, but only by way of repetition. Not all activities are like this. Some activities are atelic: They do not aim at terminal states. However much you reflect on life or spend time with your family, you cannot complete these activities. Though you will eventually stop doing them, they do not aim at a point at which there is no more of them to do.

Aristotle made the same distinction, contrasting two kinds of action or praxis: kinesis and energeia. Kinetic actions are telic and therefore incomplete. As Aristotle wrote in his “Metaphysics”: “If you are learning, you have not at the same time learned.” When you care about telic activities, projects such as writing a report, getting married or making dinner, satisfaction is always in the future or the past. It is yet to be achieved and then it is gone. Telic activities are exhaustible; in fact, they aim at their own exhaustion. They thus exhibit a peculiar self-subversion. In valuing and so pursuing these activities, we aim to complete them, and so to expel them from our lives.

Atelic activities, by contrast, do not by nature come to an end and are not incomplete. In defining such activities, we could emphasize their inexhaustibility, the fact that they do not aim at terminal states. But we could also emphasize what Aristotle does: They are fully realized in the present. “At the same time, one is seeing and has seen, is understanding and has understood, is thinking and has thought.” There is nothing you need to do in order to perform an atelic activity except what you are doing right now. If what you care about is reflecting on your life or spending time with family or friends, and that is what you are doing, you are not on the way to achieving your end: You are already there.

What would it mean, then, to live in the present, and what do we gain by doing it?

To live in the present is to appreciate the value of atelic activities like going for a walk, listening to music, spending time with family or friends. To engage in these activities is not to extinguish them from your life. Their value is not mortgaged to the future or consigned to the past, but realized here and now. It is to care about the process of what you are doing, not just projects you aim to complete.