Because Dr. Regnerus would not be interviewed, it is impossible to know his latest views about the relationship between his faith and research. But we can still ask if, in principle, belief in the divinity of Jesus could affect one’s social science. Put another way: Is there a Christian way to crunch numbers?

“The answer, in my personal opinion, is no,” said Mark Chaves, a sociologist of religion at Duke Divinity School. But, he added, religious concerns “can very profoundly shape the kinds of questions we ask, and what we’re interested in, what we think is important and so on.” So while “in the narrowest sense it doesn’t affect his computations,” Dr. Regnerus’s Christian faith may have drawn him to questions about same-sex relationships and family structure.

And a religious worldview, like any worldview, can dispose a researcher toward certain mistakes in thinking. Somebody critical of same-sex relationships may be more likely to group all such relationships together, as Dr. Regnerus did. If homosexual acts are depraved, as many religious people believe, then long-term coupling may be no better, or even worse, than bursts of promiscuity.

Christian Smith, one of Dr. Regnerus’s advisers at the University of North Carolina and now at Notre Dame agrees that a sociologist’s religion should affect only his choice of topics, not his methodology.

“I believe there is sociology that is practiced in perhaps somewhat different ways by people with different backgrounds of all sorts — racial, socioeconomic, gender and religious, among others,” Dr. Smith said. But every sociologist “operates with the same basic disciplinary approach, methods and standards of evidence.” Dr. Smith said that while he had not talked with his former student “about any possible connection of faith to topic/design,” he was “quite sure his faith did not influence the design.” But he said he could “only speculate” whether Dr. Regnerus’s faith led to his interest in the topic.

So if there is not really a Christian method in sociology, but there is a role for a self-described Christian in sociology, as Dr. Regnerus once averred, then what is that role? One can imagine several answers.

First, the religious — or atheist, for that matter — sociologist might have a set of topics that she finds particularly relevant to her beliefs. Given their traditions’ emphasis on traditional family, for example, a conservative Catholic or evangelical Protestant could reasonably gravitate toward the study of family structure.