When philosophy professor Keith Parsons posted an announcement on his blog, The Secular Outpost, explaining why he had decided to abandon philosophy of religion, he expected only his handful of regular readers to take notice. After a decade teaching philosophy of religion at the University of Houston, during which time he founded the philosophy of religion journal Philo and published over twenty books and articles in the field, Parsons hung up his hat on September 1:

I have to confess that I now regard “the case for theism” as a fraud and I can no longer take it seriously enough to present it to a class as a respectable philosophical position—no more than I could present intelligent design as a legitimate biological theory. BTW, in saying that I now consider the case for theism to be a fraud, I do not mean to charge that the people making that case are frauds who aim to fool us with claims they know to be empty. No, theistic philosophers and apologists are almost painfully earnest and honest… I just cannot take their arguments seriously any more, and if you cannot take something seriously, you should not try to devote serious academic attention to it.

To his surprise, the announcement went viral. Posted and reposted on blogs such as Leiter Reports, The Prosblogion, and Debunking Christianity, it generated hundreds of comments in the subsequent weeks about the status of the field and whether Parsons’ criticisms were warranted. “It’s not that often philosophers renounce fields!” says Brian Leiter, a philosopher at the University of Chicago, at Leiter Reports. Parsons’ incendiary choice of words likely also bore some responsibility for the reaction. “I’m afraid what precipitated the thing going viral is that I said it was a fraud, which I shouldn’t have said, because ‘fraud’ implies an intentional attempt to fool people,” Parsons says.

The “Miracle” is that People Believe At All

His word choice may have been the spark, but it landed on some particularly dry kindling: a general tension over the legitimacy of philosophy of religion in philosophy as a whole. Against the very nonreligious field of philosophy (73% of philosophers identify as atheist, according to one recent survey), the Christian-dominated subfield of philosophy of religion stands out.

“I think most philosophers basically agree with a book John Mackie wrote many years ago called The Miracle of Theism, the idea being that it was a miracle anybody could believe that,” Leiter says. To philosophers who feel like the case against God was settled hundreds of years ago, philosophy of religion often seems like apologetics, an effort to rationalize preexisting beliefs. “The brouhaha about Parsons brought to the fore something that does exist, a contempt or skepticism about the validity of philosophy of religion by many philosophers,” says John Fischer, another philosopher of religion based at the University of California Riverside, who, like Parsons, is an atheist.

Of course, post-hoc rationalization happens in other subfields as well, whether because philosophers are bringing their own personal beliefs to the discussion, or because they have already committed publicly to a particular viewpoint and thus have an incentive not to back down. “For many people, in just about any area of philosophy, if they have a professional stake in their view they’ll accept some pretty implausible results,” Fischer says. But philosophy of religion is arguably a special case.

Compared to more esoteric subfields like philosophy of language or metaphysics, philosophy of religion is much more likely to attract people with deep-seated, lifelong beliefs about the topic. Because viewpoints in philosophy of religion are so emotionally fraught and bound up with a person’s lifestyle, values, and relationships, changing one’s mind is a daunting prospect. The central point of contention—the existence of God—is most fraught of all, not to mention starkly binary. “In philosophy of religion you do have this gap—either God exists or not. There’s no middle ground,” Parsons says. However, even philosophers bent on keeping their core beliefs can help move discussions forward. As in other subfields, much of philosophy of religion consists in working out the logical implications of arguments, which is less a matter of finding the right path than mapping out which paths exist.

Even in Paleontology, the Bones are There

Take, for example, the evolution of the “argument from evil,” which holds that the existence of evil in the world is incompatible with a deity that is simultaneously all-knowing, all-powerful, and all-good. In the 1970s, several leading philosophers of religion broke the argument down into a “logical” version (that any amount of evil is logically incompatible with such a god) which most philosophers consider defeated, and an “evidential” version (that certain amounts or types of evil we observe in our world are evidence against such a god) which remains a thorny problem. “Distinguishing between the logical and the evidential arguments helped clarify the types of theistic arguments that might serve as rebuttals,” says Craig Duncan, a philosopher at Ithaca College. “So even if people aren’t changing from theism to atheism and vice versa, the positions in the field get stated with increasing sophistication.”

It’s also easier to be an atheist philosopher of religion if your main motivation is exploring interesting paths, regardless of where they begin or end. Fischer, for example, says, “I find the arguments extremely creative and subtle, and so I find it interesting to explore them even though I myself do not accept religious starting points.” (In fact, he suggested, the very pressure that some philosophers of religion feel to rationalize their beliefs may be to thank for the subfield’s high levels of creativity.) By contrast, Parsons’ background in the sciences (he obtained his doctorate in the history and philosophy of science at University of Pittsburgh) made him wary of unfettered reasoning. “There’s so little empirical grounding and constraint in philosophy. Even in paleontology, a so-called soft science, the bones are there,” Parsons says. “You can go measure them, look at them. You can’t say anything the bones won’t let you say.”

Keeping an eye on the truth was also a matter of practical importance for Parsons, who was alarmed by the support for Intelligent Design creationism among philosophy of religion’s most influential names. These include Alvin Plantinga and Peter van Inwagen, who led the subfield’s resurgence in the 1970s and ’80s, and William Lane Craig, an evangelical who popularizes the subfield’s arguments for God in widely-attended public debates. “One of the things the really active conservative Christians covet enormously, more than anything else, is intellectual respectability. And they think they have found it in some of the arguments from these philosophers of religion,” Parsons said.

Although Parsons is done arguing with a field that seems committed to a particular perspective, he concludes his post by saying that he hopes others will continue the fight. But what he doesn’t make explicit in his post is a disheartening subtext to his decision: that in our pursuit of truth, argument may only take us so far. “Philosophy of religion,” says Parsons, “is inevitably speculative and inconclusive.” Although he has no doubt that the theistic arguments for God’s existence have been thoroughly rebutted, he allows that the atheistic arguments he finds persuasive might not be nearly as persuasive to another rational person who happens to have different intuitions.

“There are certain things William Lane Craig takes to be metaphysical intuitions, like that it’s undeniable that the universe must have had a cause—and for me it’s not. My intuitions are quite different,” Parsons says. And what then? He adds, “And then, once we’ve reached that point, there’s just no further to go.”