"It is vain and useless to conceive either grief or joy for future things, which perhaps shall never come to pass. But it is in human nature to be deluded with such imaginations." The Imitation of Christ, Book 3, Chp. 30.
Why is it in our nature to be deluded with such imaginations? If we're meant to be deluded, maybe we should allow ourselves to be deluded? I assume a'Kempis refers to our lower nature, but still: there is something in us that tends to look forward and backward. Every tendency, even those that tend to be sinful, has a root in creation. The sin of fornication, in love of other and the procreation of children; the sin of greed, in love of the things of creation; etc.
So we have a tendency to look forward and backward.
The forward part is easily (if perhaps superficially) explained: We look forward to a better life, to heaven. This place isn't meant to be our ultimate stomping grounds.
But what about backward? We could say it is part of the same tendency: we're not wholly happy here, so we look anywhere but now. We should look forward (to heaven), but the tendency sin-warps into backward glances. Could be. Socrates might say it's part of our nature because we pre-existed among the Forms: we had a better existence before we were born.
