Ordinarily our life is always incomplete, in the strongest sense of the term, because we project all our hopes, all our aspirations, all our attention on the future, telling ourselves that we will be happy when we will have attained this or that goal. We are scared as long as the goal is not attained, but if we attain it, already it no longer interests us and we continue to run after something else. We do not live, we hope to live, we are waiting to live. Stoics and Epicureans invite us, then, to effect a total conversion of our relation to time, to live in the only moment we live in, that is, the present; to live not in the future but, on the contrary, as though there were no future, as though we only had this day, only this moment, to live; to live it then as well as possible, as though it were the last day, the last moment of our life, in our relationship to ourselves and to those around us. It is not a question here of false tragedy, which would be ridiculous, but of a way to discover everything that can be possessed in an instant. First of all, we can realize an action well done, done for itself, with attention and consciousness. We can tell ourselves, I apply myself at concentrating on my action of this moment; I do it as well as possible. We can also tell ourselves, I am here, alive, and this is enough; that is, we can become conscious of the value of existence - or one can repeat Montaigne’s inexhaustible sentence on this subject, saying to the one who has the impression of having done nothing, 'What? Have you not lived? It is not only the most fundamental, but the most illustrious of your occupations.’ … suffice it to say briefly that to live in the present is to live as though we were seeing the world for the first and for the last time. Every present moment can thus be a moment of happiness, whether it is the pleasure of existing or the joy of doing things well.
- Pierre Hadot, The Present Alone is Our Happiness