Blaise Pascal, Pascal's Pensees, (New York: E.P. Dutton and Co., 1958), pp. 49-50
We do not rest satisfied with the present. We anticipate that future as too slow in coming, as if in order to hasten its course; or we recall the past, to stop its too rapid flight. So imprudent are we that we dream of those times which are no more, and thoughtlessly overlook that which alone exists. For the present is generally painful to us. We conceal it from our sight, because it troubles us; and if it be delightful to us, we regret to see it pass away. We try to sustain it by the future, and think of rearranging matters which are not in our power, for a time which we have no certainty of reaching.
Let each one examine his thoughts, and he will find them all occupied with the past and the future. We scarcely ever think of the present; and if we think of it, it is only to take light from it to arrange the future. The present is never our end. So we never live, but we hope to live; and, as we are always preparing to be happy, it is inevitable we should never be so.