In its wicked aspect, then, the heart of the world (for it is odd to think that the world has more than one heart--a worst, a better, etc.) is a bigger, fatter book than a devotional primer intended to instruct gentle readers in the cultivation of character (and gardens). God has mercifully arranged it so that the bigger book is illegible. But the illegible book is precisely what those desperate men found in their hearts on their deathbeds, what leads us back to the hotel café in the heart of London, and what would seem to be the dark twin of the thin, good book. What is going on here?
Poe had his finger on the strand of thought about evil that informed Aquinas's disputation. Like natural evil, moral evil--or, as Poe puts it, "crime"--has no independent essence. It is instead parasitic on what's good. And the parasitism may explain the uncanny multiplication of pages in that unwieldy, illegible book of the bad potential in the heart. The problem is this: not only is there potential badness in any heart that requires careful cultivation (which is, on this view, any maturing human heart), that potential isn't constrained by any independently describable essential quality. Evil isn't its own thing. Because of this, it can take shape in surprisingly many, infinitely many, unexpected, novel ways.
This is easy enough to see with so-called natural evils. There are, for example, infinitely many sorts of accidents of birth or fortune that can interfere with a living thing's vital processes. Take our species, for example. Think of actuarial tables, warning labels, the results of research into the human genome, lore and technical instruction about what to do in case of fire, earthquake, volcanic eruption, flood and the like. These constitute fat books of natural evil. Concepts such as risk, defect, injury, illness and damage give a clear sense of the way in which natural evil is parasitic upon good. There is how things are supposed to go for a living human being (which needn't be how things actually do go for any of us). Then there are all the ways that things can go wrong, indexed to a sobering array of points of human vulnerability. And while we are unable to give a full account of how things are supposed to go for a human organism (actually, in this case, we seem to have clearer access to the bad than we do to an uncontroversial account of all-around human health), we have learned how to chart many possible points of disruption, disorder and so on.
These ills are measured in degrees representing various ways of falling away from how things are supposed to be with one of us. Each fall involves privation of good. And, in spite of all this knowledge, people who work in hospital emergency rooms will tell you that there is an abiding sense of novelty in the sheer variety of ways that things can go wrong. My sister the surgical technician was talking to me once, describing a long day in emergency given over to an especially arduous operation, when she broke off abruptly and said, "Who knew that anyone could have that kind of trouble with a lawnmower?"
And what of manmade badness done to or made for one or more of us at the hands of one or more of our fellows? Poe's suggestion is that potentiality for wrongdoing is ubiquitous among us. If we pair the size of the book of the heart's bad aspect with what stopped our sociologically inclined narrator's happy categorization of Londoners--the singular face, the "absolute idiosyncrasy" of expression--we could go so far as to suggest that ubiquitous, indeterminate possibilities of human evil individuate human beings, pick out ones from others, and make each of us distinctive.
