"A word to the wise ain't necessary --
it's the stupid ones that need the advice."
Chesterton on Dickens
This heartiness and vivacity in the villains of Dickens is worthy of note because it is directly connected with his own cheerfulness. This is a truth little understood in our time, but it is a very essential one. If optimism means a general approval, it is certainly true that the more a man becomes an optimist the more he becomes a melancholy man. If he manages to praise everything, his praise will develop an alarming resemblance to a polite boredom. He will say that the marsh is as good as the garden; he will mean that the garden is as dull as the marsh. He may force himself to say that emptiness is good, but he will hardly prevent himself from asking what is the good of such good. This optimism does exist -- this optimism which is more hopeless than pessimism -- this optimism which is the very heart of hell. Against such an aching vacuum of joyless approval there is only one antidote -- a sudden and pugnacious belief in positive evil. This world can be made beautiful again by beholding it as a battlefield. When we have defined and isolated the evil thing, the colours come back into everything else. When evil things have become evil, good things, in a blazing apocalypse, become good. There are some men who are dreary because they do not believe in God; but there are many others who are dreary because they do not believe in the devil. The grass grows green again when we believe in the devil, the roses grow red again when we believe in the devil.
No man was more filled with the sense of this bellicose basis of all cheerfulness than Dickens. He knew very well the essential truth, that the true optimist can only continue an optimist so long as he is discontented. For the full value of this life can only be got by fighting; the violent take it by storm. And if we have accepted everything, we have missed something -- war. This life of ours is a very enjoyable fight, but a very miserable truce. And it appears strange to me that so few critics of Dickens or of other romantic writers have noticed this philosophical meaning in the undiluted villain. The villain is not in the story to be a character; he is there to be a danger -- a ceaseless, ruthless, and uncompromising menace, like that of wild beasts or the sea. For the full satisfaction of the sense of combat, which everywhere and always involves a sense of equality, it is necessary to make the evil thing a man; but it is not always necessary, it is not even always artistic, to make him a mixed and probable man. In any tale, the tone of which is at all symbolic, he may quite legitimately be made an aboriginal and infernal energy. He must be a man only in the sense that he must have a wit and will to be matched with the wit and will of the man chiefly fighting. The evil may be inhuman, but it must not be impersonal, which is almost exactly the position occupied by Satan in the theological scheme.
from Charles Dickens, The Last of the Great Men,
by G. K. Chesterton