Evil is but the shadow, that, in this world, always accompanies good. You may have a world without shadow, but it will be a world without light - a mere dim, twilight world. If you would deepen the intensity of the light, you must be content to bring into deeper blackness and more distinct and definite outline, the shade that accompanies it.
The truest definition of evil is that which represents it as something contrary to nature. Evil is evil because it is unnatural. A vine which should bear olive-berries - an eye to which blue seems yellow, would be diseased. An unnatural mother, an unnatural son, an unnatural act, are the strongest terms of condemnation.
You may tame the wild beast; the conflagration of the forest will cease when all the timber and the dry wood are consumed; but you cannot arrest the progress of that cruel word which you uttered carelessly yesterday or this morning.
If there be anything common to us by nature, it is the members of our corporeal frame; yet the apostle taught that these, guided by the spirit as its instruments, and obeying a holy will, become transfigured, so that, in his language, the body becomes a temple of the Holy Ghost, and the meanest faculties, the lowest appetites, the humblest organs are ennobled by the spirit mind which guides them.