Blake wrote the Marriage of Heaven and Hell. If I have written of their Divorce, this is not because I think myself a fit antagonist for so great a genius, nor even becasue I feel at all sure that I know what he meant. But in some sense or other the attempt to make that marriage is perennial. The attempt is based on the belief that reality never presents us with an absolutely unavoidable ‘either-or’; that, granted skill and patience and (above all) time enough, some way of embracing both alternatives can always be found; that mere development or djustment or refinement will somehow turn evil into good without our being called on for a final and total rejection of anything we should like to retain. This belief I take to be a disastrous error. You cannot take all luggage with you on all journeys; on one journey even your right hand and your right eye may be among the things you have to leave behind. We are not living in a world where all roads are radii of a circle and where all, if followed long enough, will therefore draw gradually nearer and finally meet at the centre: rather in a world where every road, after a few miles, forks into two, and each of those into two again, and at each fork you must make a decision. Even on the biological level life is not like a river but like a tree. It does not move towards unity but away from it and the creatures grow further apart as they increase in perfection. Good, as it ripens, becomes continually more different not only from evil but from other good.
I do not think that all who choose wrong roads perish; but their rescue consists in being put back on the right road. A sum can be put right: but only by going back till you find the error and working it afresh from that point, never by simply going on. Evil can be undone, but it cannot ‘develop’ into good. Time does not heal it. The spell must be unwound, bit by bit, ‘with backward mutters of dissevering power’—or else not. It is still ‘either-or’. If we insist on keeping Hell (or even Earth) we shall not see Heaven: if we accept Heaven we shall not be able to retain even the smallest and most intimate souvenirs of Hell.
C.S. Lewis, The Great Divorce, pref. vii–viii
Thanks, dear reader, should you ever find me, for being my gadfly.