If time is correctly defined as an infinite succession, it most likely is also defined as the present, the past, and the future. This distinction, however, is incorrect if it is considered to be implicit in time itself, because the distinction appears only through the relation of time to eternity and through the reflection of eternity in time. If in the infinite succession of time a foothold could be found, i.e., a present, which was the dividing point, the division would be quite correct. However, precisely because every moment, as well as the sum of the moments, is a process (a passing by), no moment is a present, and accordingly there is in time neither present, nor past, nor future. If it is claimed that this division can be maintained, it is because the moment is spatialized, but thereby the infinite succession comes to a halt, it is because representation is introduced that allows time to be represented instead of being thought. Even so, this is not correct procedure, for even as representation, the infinite succession of time is an infinitely contentless present (this is the parody of the eternal). . . .
The present, however, is not a concept of time, except precisely as something infinitely contentless, which again is the infinite vanishing. If this is not kept in mind, no matter how quickly it may disappear, the present is posited, and being posited it again appears in the categories: the past and the future.
The eternal, on the contrary, is the present. For thought, the eternal is the present in terms of an annulled succession (time is the succession that passes by). For representation, it is a going forth that nevertheless does not get off the spot, because the eternal is for representation the infinitely contentful present. So also in the eternal there is no division into the past and the future, because the present is posited as the annulled succession.
Time is, then, infinite succession; the life that is in time and is only of time has no present. In order to define the sensuous life, it is usually said that it is in the moment and only in the moment. By the moment, then, is understood that abstraction from the eternal that, if it is to be the present, is a parody of it. The present is the eternal, or rather, the eternal is the present, and the present is full. . . .
The moment signifies the present as that which has no past and no future, and precisely in this lies the imperfection of the sensuous life. The eternal also signifies the present as that which has no past and no future, and this is the perfection of the eternal.
--Søren Kierkegaard, The Concept of Anxiety, pp. 85-87