There can, that is to say, be no theater unless bad things happen, unless there are terrible problems, insoluble knots; without them, there would be nothing for the characters to do. That "doing" gives us the very word by which we refer to what happens on stage: "drama" comes from the Greek drân, "to do" or "to act." When we go to the theater, we want to see characters doing things. Bad things, preferably.
The inherent dramatic interest of badness helps explain the abiding fascination exerted by bad, or at the very least tormented, characters. In opera as in spoken drama, our attention tends to be focused either on the outright villains—the figures who engineer the bad things that make drama dramatic—or on those characters whose ostensible goodwill is complicated by other qualities, either dark or excessive, that create the titanic dilemmas with which they must struggle so interestingly. But in characters who are saintly—who are without the overweening ambitions that fuel so many plots, who approach life's crises reasonably rather than passionately, who want to be helpful rather than to prevail—we have little interest. For Antigone, with her outsized allegiances and inflexible righteousness, for Carmen, with her transgressive seductiveness and fatal in-dependent streak, we feel an abiding interest—even, though we might not like to admit it, allegiance—but does anyone really want to see a play about Ismene, or sit through an opera about Micaela? Could you even write such a play or opera? What would an opera that contemplates a blameless protagonist look like? (As opposed to an opera about a protagonist whose goodness is merely the refractive lens to examine a villain's badness: Billy Budd, say.)
Mendelsohn, reflecting on the famous Einstein on the Beach, believes Philip Glass may have the answer:
Whatever happened in this work, it wasn't the kind of happening—the "doing"—that got done in traditional drama, the troubled Western arc from knotting to loosening. Instead, Glass's music drama was "doing" something in a rather more Eastern mode—as if the mantric repetitions of the music were a kind of meditative medium (as they can indeed be, in Eastern religions) for achieving a kind of spiritual heightening: not an ideal position from which to witness Medea's infanticide or Peter Grimes's anguish, perhaps, but surely an appropriate state from which to contemplate other, purer characters. (Oliver Messiaen understood this too, as his own rather hypnotic, meditative Saint Francis of Assisi demonstrates.) Einstein would, in fact, be the first element of what turned out to be a trilogy of Glass operas about saintly men—the other two being Satyagraha (1980), about Mohandas Gandhi's evolution into a champion of nonviolent political resistance, and Akhnaten (1983), about the Egyptian pharaoh who attempted to establish monotheistic worship.