Via Anecdotal Evidence, Roger Scruton:
Nostalgia is an unhealthy state of mind. But the study, love and emulation of the past are necessary to our self-understanding. All that has gone most wrong in our century has proceeded from a morbid obsession with the future—a belief in 'new dawns', 'revolutionary transformations', and resurrected nations on the march. The past, unlike the future, can be known, understood and adapted to our current uses. When we cast ourselves free from it, we are swept away by outside forces, adrift on the oceanic tide of happening. The future, which we cannot describe, begins to seem inevitable. This surrender to the unknown persists, despite all the crime and destruction that have been wrought in its name.