Unfortunately, few Latin dicta are more helpful for interpreting reality than this. Corruptio optimi pessima. Indeed, the corruption of the best is the worst.
There is, all the same, a stark proportion to reality; and because the world is an ordered place—a kosmos—it must be so. This is not to say, however, that what is best depends upon what is worst in order to exist. Manichaeism was proven false a long time ago. And this is the first thing our little sentence teaches us: we are dealing with corruption, decay, deficit, darkening, a breaking down of something that ought to be otherwise—not the acknowledgement of some necessary opposite of goodness that is a thing unto itself. The darkness to which we refer here is always a departure, not a complement.
We are also in the territory of Saint Augustine’s insight: that evil is a privatio boni; a privation of the good. What is good is the fundamental reality, not what is evil. Thus evil, on the other hand, has no form of its own; it is the shadowy space where a good ought to be.
Creation is what is. Revelation is what is. God himself is the bedazzling I AM, and all truth proceeds from him. Truth is The Best. If this can be grasped, it stands perfectly to reason that the more dramatic a departure from The Best, the more profound the worst becomes and appears. Thus we have no reason to be caught off guard. Corruptio optimi pessima is not an esoteric principle, something that only the clever and few can see; it is the purest common sense.
If all that be true, then are we not allowed at least some degree of serenity? There is peace to be had in the straightforward acknowledgement that something is wrong. Serenity is possible because The Best is the most real and lasting. A dramatic corruption still points to The Best from which it fell and decayed; otherwise, we would not know it to be the corruption it is. Thus, peace is possible because if some circumstance, or someone, has swerved from The Best, there is always hope for a return.