We form an idea of eternity by denying the imperfection of the now. What imperfection?
Imperfection is potentiality or indetermination. To freeze everything in the now would not be an improvement for the things contained within it: they need the sort of ontological openness to the future that gives them space to exist. Again, temporal things exist in the temporal present, but this present can only be visualized as cramped and narrow. Of itself, it lacks all of its history, and we could not imagine a more cramped prison than the mere present, even if William James is correct in making the present last a few seconds. Ignore for the moment the relation that the present has to its history. What is this “openness” to the future? We are certain that our existence is such that it needs this openness or necessarily generates this openness.
We imagine this possibility in spacial terms. The present is a point or a short dash, the future is a long line extending to the left. But this hides precisely the crux of the problem. The necessity of the future is precisely its possibility and indetermination. We can see this at least as clearly as we see the absolute fixity of our history (“even God cannot change the past”, etc.). But space is never given in its indetermination or possibility. It can only be given as actual, as there to move into. We cannot look at the future as we look at a landscape. The present does not open into the future like a door opens up into a room. Space opens into the given and therefore into the necessary. The present is open to the possible.
But when sense can we make of openness to possibility, or a necessary relation to the possible? It is a trick of the imagination to put possibilities in front of us like a field into which we enter, if for no other reason than by putting the indeterminate possible in the future it can cease to be an indeterminate possible, because some possible things are actualized. Possibility is present to us now. But if we place the field of possibility in the present, then what is open to it? Isn’t it the present itself that we see as open to the field of possibilities outside of the narrow and cramped strictures of the present itself?