Forgetfulness is necessary to remembrance.  Ideas are retained by renovation of that impression which time is always wearing away, and which new images are striving to obliterate.  If useless thoughts could be expelled from the mind, all the valuable parts of our knowledge would more frequently recur, and every recurrence would reinstate them in their former place.

It is impossible to consider, without some regret, how much might have been learned, or how much might have been invented, by a rational and vigorous application of time, uselessly or painfully passed in the revocation of events, which have left neither good nor evil behind them, in grief for misfortunes either repaired or irreparable, in resentment of injuries known only to ourselves, of which death has put the authors beyond our power.

Philosophy has accumulated precept upon precept, to warn us against the anticipation of future calamities.  All useless misery is certainly folly, and he that feels evils before they come may be deservedly censured; yet surely to dread the future is more reasonable than to lament the past.  The business of life is to go forwards:  he who sees evil in prospect meets it in his way; but he who catches it by retrospection turns back to find it.  That which is feared may sometimes be avoided, but that which is regretted to-day may be regretted again to-morrow.

Regret is indeed useful and virtuous, and not only allowable but necessary, when it tends to the amendment of life, or to admonition of errour which we may be again in danger of committing.  But a very small part of the moments spent in meditation on the past, produce any reasonable caution or salutary sorrow.  Most of the mortifications that we have suffered, arose from the concurrence of local and temporary circumstances, which can never meet again; and most of our disappointments have succeeded those expectations, which life allows not to be formed a second time.

It would add much to human happiness, if an art could be taught of forgetting all of which the remembrance is at once useless and afflictive; if that pain which never can end in pleasure could be driven totally away, that the mind might perform its functions without incumbrance, and the past might no longer encroach upon the present.

Little can be done well to which the whole mind is not applied; the business of every day calls for the day to which it is assigned; and he will have no leisure to regret yesterday’s vexations who resolves not to have a new subject of regret to-morrow.

But to forget or to remember at pleasure, are equally beyond the power of man.  Yet as memory may be assisted by method, and the decays of knowledge repaired by stated times of recollection, so the power of forgetting is capable of improvement.  Reason will, by a resolute contest, prevail over imagination, and the power may be obtained of transferring the attention as judgment shall direct.