In Book 10 of Milton’s “Paradise Lost,” Adam asks the question so many of his descendants have asked: why should the lives of billions be blighted because of a sin he, not they, committed? (“Ah, why should all mankind / For one man’s fault… be condemned?”) He answers himself immediately: “But from me what can proceed, / But all corrupt, both Mind and Will depraved?” Adam’s Original Sin is like an inherited virus. Although those who are born with it are technically innocent of the crime – they did not eat of the forbidden tree – its effects rage in their blood and disorder their actions.

God, of course, could have restored them to spiritual health, but instead, Paul tells us in Romans, he “gave them over” to their “reprobate minds” and to the urging of their depraved wills. Because they are naturally “filled with all unrighteousness,” unrighteous deeds are what they will perform: “fornication, wickedness, covetousness, maliciousness . . . envy, murder . . . deceit, malignity.” “There is none righteous,” Paul declares, “no, not one.”

It follows, then (at least from these assumptions), that the presence of evil in the world cannot be traced back to God, who opened up the possibility of its emergence by granting his creatures free will but is not responsible for what they, in the person of their progenitor Adam, freely chose to do.

What Milton and Paul offer (not as collaborators of course, but as participants in the same tradition) is a solution to the central problem of theodicy – the existence of suffering and evil in a world presided over by an all powerful and benevolent deity. The occurrence of catastrophes natural (hurricanes, droughts, disease) and unnatural (the Holocaust ) always revives the problem and provokes anguished discussion of it. The conviction, held by some, that the problem is intractable leads to the conclusion that there is no God, a conclusion reached gleefully by the authors of books like “The God Delusion,” “God Is Not Great” and “The End of Faith.” (See discussion here, here and here.)

Now two new books (to be published in the coming months) renew the debate. Their authors come from opposite directions – one from theism to agnosticism, the other from atheism to theism – but they meet, or rather cross paths, on the subject of suffering and evil.

Bart D. Ehrman is a professor of religious studies and his book is titled “God’s Problem: How the Bible Fails to Answer Our Most Important Question – Why We Suffer.” A graduate of Princeton Theological Seminary, Ehrman trained to be a scholar of New Testament Studies and a minister. Born-again as a teenager, devoted to the scriptures (he memorized entire books of the New Testament), strenuously devout, he nevertheless lost his faith because, he reports, “I could no longer reconcile the claims of faith with the fact of life . . . I came to the point where I simply could not believe that there is a good and kindly disposed Ruler who is in charge.” “The problem of suffering,” he recalls, “became for me the problem of faith.”

Much of the book is taken up with Ehrman’s examination of biblical passages that once gave him solace, but that now deliver only unanswerable questions: “Given [the] theology of selection – that God had chosen the people of Israel to be in a special relationship with him – what were Ancient Israelite thinkers to suppose when things did not go as planned or expected? . . . . How were they to explain the fact that the people of God suffered from famine, drought, and pestilence?”

Ehrman knows and surveys the standard answers to these questions – God is angry at a sinful, disobedient people; suffering is redemptive, as Christ demonstrated on the cross; evil and suffering exist so that God can make good out of them; suffering induces humility and is an antidote to pride; suffering is a test of faith – but he finds them unpersuasive and as horrible in their way as the events they fail to explain: “If God tortures, maims and murders people just to see how they will react – to see if they will not blame him, when in fact he is to blame – then this does not seem to me to be a God worthy of worship.”

And as for the argument (derived from God’s speech out of the whirlwind in the Book of Job) that God exists on a level far beyond the comprehension of those who complain about his ways, “Doesn’t this view mean that God can maim, torment, and murder at will and not be held accountable? . . . . Does might make right?”

These questions are as old as Epicurus, who gave them canonical form: “Is God willing to prevent evil but not able? Then he is impotent. Is he able but not willing? Then he is malevolent. Is he both able and willing? Whence, then, evil.”

Many books of theology and philosophy have been written in response to Epicurus’s conundrums, but Ehrman’s isn’t one of them. What impels him is not the fascination of intellectual puzzles, but the anguish produced by what he sees when he opens his eyes. “If he could do miracles for his people throughout the Bible, where is he today when your son is killed in a car accident, or your husband gets multiple sclerosis? . . . I just don’t see anything redemptive when Ethiopian babies die of malnutrition.”

The horror of the pain and suffering he instances leads Ehrman to be scornful of those who respond to it with cool abstract analyses: “What I find morally repugnant about such books is that they are so far removed from the actual pain and suffering that takes place in our world.”

He might have been talking about Antony Flew’s “There Is a God: How the World’s Most Notorious Atheist Changed His Mind.” Flew, a noted professor of philosophy, announced in 2004 that after decades of writing essays and books from the vantage point of atheism, he now believes in God. “Changed his mind” is not a casual formulation. Flew wouldn’t call what has happened to him a conversion, for that would suggest something unavailable to analysis. His journey, he tells us, is best viewed as “a pilgrimage of reason,” an extension of his life-long habit of “following the argument no matter where it leads.”

Where it led when he was a schoolboy was to the same place Ehrman arrived at after many years of devout Christian practice: “I was regularly arguing with fellow sixth formers that the idea of a God who is both omnipotent and perfectly good is incompatible with the manifest evils and imperfections of the world.” For much of his philosophical career, Flew continued the argument in debates with a distinguished list of philosophers, scientists, theologians and historians. And then, gradually and to his own great surprise, he found that his decades-long “exploration of the Divine ha[d] after all these years turned from denial to discovery.”

What exactly did he discover? That by interrogating atheism with the same rigor he had directed at theism, he could begin to shake the foundations of that dogmatism. He poses to his former fellow atheists the following question: “What would have to occur or have occurred to constitute for you a reason to at least consider the existence of a superior Mind.” He knows that a cornerstone of the atheist creed is an argument that he himself made many times – the sufficiency of the materialist natural world as an explanation of how things work. “I pointed out,” he recalls, that “even the most complex entities in the universe – human beings – are the products of unconscious physical and mechanical forces.”

But it is precisely the word “unconscious” that, in the end, sends Flew in another direction. How, he asks, do merely physical and mechanical forces – forces without mind, without consciousness – give rise to the world of purposes, thoughts and moral projects? “How can a universe of mindless matter produce beings with intrinsic ends [and] self-replication capabilities?” In short (this is the title of a chapter), “How Did Life Go Live?”

Flew does not deny the explanatory power of materialist thought when the question is how are we to understand the physical causes of this or that event or effect. He’s is just contending that what is explained by materialist thought – the intricate workings of nature – itself demands an explanation, and materialist thought cannot supply it. Scientists, he says, “are dealing with the interaction of chemicals, whereas our questions have to do with how something can be intrinsically purpose-driven and how matter can be managed by symbol processing?” These queries, Flew insists, exist on entirely different levels and the knowledge gained from the first can not be used to illuminate the second.

In an appendix to the book, Abraham Varghese makes Flew’s point with the aid of an everyday example: “To suggest that the computer ‘understands’ what it is doing is like saying that a power line can meditate on the question of free will and determinism or that the chemicals in a test tube can apply the principle of non-contradiction in solving a problem, or that a DVD player understands and enjoys the music it plays.”

How did purposive behavior of the kind we engage in all the time – understanding, meditating, enjoying – ever emerge from electrons and chemical elements?

The usual origin-of-life theories, Flew observes, are caught in an infinite regress that can only be stopped by an arbitrary statement of the kind he himself used to make: “ . . . our knowledge of the universe must stop with the big bang, which is to be seen as the ultimate fact.” Or, “The laws of physics are ‘lawless laws’ that arise from the void – end of discussion.” He is now persuaded that such pronouncements beg the crucial question – why is there something rather than nothing? – a question to which he replies with the very proposition he argued against for most of his life: “The only satisfactory explanation for the origin of such ‘end-directed, self-replicating’ life as we see on earth is an infinitely intelligent Mind.”

Will Ehrman be moved to reconsider his present position and reconvert if he reads Flew’s book? Not likely, because Flew remains throughout in the intellectual posture Ehrman finds so arid. Flew assures his readers that he “has had no connection with any of the revealed religions,” and no “personal experience of God or any experience that may be called supernatural or religious.” Nor does he tells us in this book of any experience of the pain and suffering that haunts Ehrman’s every sentence.

Where Ehrman begins and ends with the problem of evil, Flew only says that it is a question that “must be faced,” but he is not going to face it in this book because he has been concerned with the prior “question of God’s existence.” Answering that question affirmatively leaves the other still open (one could always sever the Godly attributes of power and benevolence, and argue that the absence of the second does not tell against the reality of the first).

Flew is for the moment satisfied with the intellectual progress he has been able to make. Ehrman is satisfied with nothing, and the passion and indignation he feels at the manifest inequities of the world are not diminished in the slightest when he writes his last word.

Is there a conclusion to be drawn from these two books, at once so similar in their concerns and so different in their ways of addressing them? Does one or the other persuade?

Perhaps an individual reader of either will have his or her mind changed, but their chief value is that together they testify to the continuing vitality and significance of their shared subject. Both are serious inquiries into matters that have been discussed and debated by sincere and learned persons for many centuries. The project is an old one, but these authors pursue it with an energy and goodwill that invite further conversation with sympathetic and unsympathetic readers alike.

In short, these books neither trivialize their subject nor demonize those who have a different view of it, which is more than can be said for the efforts of those fashionable atheist writers whose major form of argument would seem to be ridicule.

(In an article published Sunday — November 4 — in the New York Times Magazine, Mark Oppenheimer more than suggests that Flew, now in his 80’s, did not write the book that bears his name, but allowed Roy Varghese (listed as co-author) to compile it from the philosopher’s previous writings and some extended conversations. Whatever the truth is about the authorship of the book, the relation of its argument and trajectory to the argument and trajectory of Ehrman’s book stands.)

Stanley Fish is the Davidson-Kahn Distinguished University Professor and a professor of law at Florida International University, in Miami, and dean emeritus of the College of Liberal Arts and Sciences at the University of Illinois at Chicago. He has also taught at the University of California at Berkeley, Johns Hopkins and Duke University. He is the author of 10 books.