Naturalism is a commitment to explaining the world in terms of natural properties and causes, as opposed to supernatural or spiritual explanations. The only kind of theism admitted by naturalism is the kind that assumes a deity set natural properties and causes in motion and does not otherwise intervene.
Naturalists come in two flavors. Philosophical naturalists are committed to the position that only natural properties and causes exist. Methodological naturalists are willing to concede the possibility of supernatural causes but are committed to acting as if they don’t exist.
Why should methodological naturalists adopt such a curious position? The problem with supernatural explanations is that there are so many of them and they are so difficult to falsify. Has one person’s conception of God ever falsified another person’s conception on the basis of evidence? Or consider the hypothesis that God created the world to fool people into thinking that evolution occurs. How can that hypothesis possibly be falsified? As a third example, consider the flying spaghetti monster, a deity invented to poke fun at religion. It is ridiculous, but is there any way to prove that it doesn’t exist? Because there is no way to sort among supernatural explanations, methodological naturalists stick to naturalistic explanations for purely practical reasons.
Any historian worth his or her salt is a methodological naturalist—and that includes historians of religion. Even many theologians are methodological naturalists because they feel it is important to base their theology on the best knowledge of what actually happened during the biblical period.
When I began studying religion from an evolutionary perspective—now over 15 years ago—I was amazed to discover the sheer volume of historical scholarship on religions around the world and throughout history. A lot more people study religion than evolution! And the quality of their scholarship is typically very good. In other words, they hold each other accountable for their factual claims and enough historical information is available for the biblical period that certain facts have become very well established.
To see why this is worth our attention today, consider the Christian concept of the resurrection—that we will be judged upon our death and sent to either heaven or hell. Many (not all) Christians believe in this as a literal truth. To a methodological naturalist, it is a belief that arose at a certain time and place in history and spread in competition against other beliefs. How much can historians of religion tell us about the concept of the resurrection?
A lot, it turns out. My main source is a book titled “Resurrection: The Power of God for Christians and Jews” by Kevin J. Madigan (a Christian) and Jon B. Levenson (a Jew). Both are professors at Harvard University’s Divinity School, which makes them theologians, but they still have a commitment to historical scholarship that binds them to methodological naturalism.
According to Madigan and Levenson, the concept of the resurrection originated before the birth of Christ but relatively late in the history of Judaism. The first unmistakable description in the Hebrew Bible is Daniel 12:1-3, which prophesies that a great prince will appear during a time of trouble and that the dead will awake, some to eternal life, others to everlasting abhorrence.
Madigan and Levenson continue (p 316): “One of the most secure and long-lived contributions of modern biblical studies is the dating of Daniel to the time of the Seleucid persecution of 167-164 B.C.E.” That is the beauty of methodological naturalism. Even though the events took place long ago and the documentation is fragmentary, there is sufficient evidence that can be pieced together like a detective story for historians to reach a consensus on a question such as when a given document was written.
What beliefs in the afterlife existed among the Jews before the concept of the resurrection? Primarily the concept of Sheol, a gloomy place that everyone goes to regardless of whether they were good or bad. But even Sheol is mentioned infrequently in the Hebrew Bible—fewer than 70 times compared with roughly a thousand references to death. Here is Madigan and Levenson again: ““Sheol” never occurs in the many narrative accounts of deaths, whether of patriarchs, kings, prophets, priests, or ordinary people, whether of Israelite or foreigner, of righteous or wicked. Also, “Sheol” is entirely absent from legal material, including the many laws which prescribe capital punishment or proscribe necromancy. This means that “Sheol” is very much a term of personal engagement.”
“Personal engagement” means the circumstances of one’s death. Judging by what they wrote, the ancient Jews contemplated death with composure as long as they had been successful in life. The horrifying prospect was to die without accomplishing anything. According to Ruth Rosenberg, another scholar of the period, “Whenever death is due to unnatural causes, Sheol is mentioned. Whenever death occurs in the course of nature, Sheol does not appear.”
If the concept of the resurrection originated during the Seleucid persecution, what was the social context? The challenge facing the Jews at that time was Antiochus IV, a Hellenistic monarch, and the main problem was not persecution but the fact that many Jews were attracted to Hellenistic culture. The conflict reflected a division among the Jews, not a common threat to all Jews. According to the Book of Daniel, eternal life would be granted to Jews who maintained the traditional ways and all other Jews would suffer everlasting abhorrence. Belief in the resurrection was arguably a key factor that enabled the Maccabees, the traditionalist faction, to resist Antiochus in a victory that is still celebrated in the festival of Hanukkah. Based on other historical scholarship, Madigan and Levenson think that the concept of the resurrection originated before the Maccabean revolt but in the same social context of groups of Jews that had separated themselves from other Jews and regarded themselves as the chosen people.
These facts, derived by historians committed to methodological naturalism, were a revelation to me when I first learned about them. Everyone knows that Christianity was historically derived from Judaism, yet belief in the resurrection, which is central to Christianity, was entirely absent for most of the history of Judaism and remains relatively marginal compared to the motivation to establish the nation of Israel on earth. A common theory of religion is that it functions to allay our fear of death. If that were the case, then all religions would include beliefs about a pleasant afterlife, a hypothesis that is disproven by Judaism (and many pagan religions during the same period). Even the concept of the resurrection in its original form had little to do with personal anxiety about death and much more to do with fostering solidarity in the face of a threat to one’s group.
The same facts are revelatory for religious believers, but in a different way. Religious beliefs evolve. They originate in certain times and places and spread or go extinct in competition with other beliefs. Those that succeed often (not always) do so by creating strong communities–like the concept of the resurrection in its original form. As for that concept, it has mutated many times and grown into a bushy tree of concepts during the 2000-year history of Abrahamic religions. Every branch can be studied as a product of cultural evolution in the same way that I have recounted for the original concept, thanks to an army of historians committed to methodological naturalism.
Many religious beliefs that evolve by cultural evolution do not correspond to factual reality. They evolved because they were useful, not because they were true (usefulness can be considered a kind of truth, but one that must be distinguished from factual truth). This creates a dilemma for many religious believers. If they commit to methodological naturalism, then they must alter their theology to conform to the facts. Whatever Madigan and Levenson mean by the power of God in the title of their book, it is not the same as Paul, who wrote that if the resurrection was a mere fiction, then the entire religion was a lie. If religious believers abandon methodological naturalism, then they are forced to deny not only the laws of physics and the facts biological evolution, but the histories of their own religions.