What if there is something church leaders can do about mainline decline? And what if it’s something for which we might actually have some training?

These days the “reasons for mainline decline” arguments fall into two distinct camps: theological and sociological. Most recently, Ross Douthat and Diana Butler Bass went toe-to-toe in an extremely interesting exchange.

Douthat struck first in his New York Times column, arguing that the theology of liberal Christianity -- or the lack thereof -- is to blame. In Douthat’s mind, there just isn’t enough “there” there in our liberal theology to attract new adherents. Recover our theology, Douthat believes, and we will regain not only our souls but our standing in the world.

In her response, Diana Butler Bass draws on sociological findings that mainline denominations are not the only churches in decline. And since evangelical and white Roman Catholic numbers are waning as well, she argues, liberal theology can’t be the culprit. Bass goes so far as to defend a burgeoning liberal renaissance, cleverly reversing Douthat’s question -- “Can liberal Christianity be saved?” -- to muse, “Can liberal churches save Christianity?”

According to sociologists such as Duke’s Mark Chaves, Bass’ argument appears to be the stronger at first. The mainline declined, Chaves shows in “American Religion: Contemporary Trends,” for a number of reasons but primarily because the birthrates in these churches declined. As more theologically conservative traditions have experienced birthrate declines in recent years, Chaves notes, their numbers have leveled off as well.

While I greatly respect Bass and Chaves, this demographics-is-destiny view leaves mainline Protestant leaders like me without much to do.

I can’t abandon my beliefs to attract new members, as Douthat suggests. Nor do I really want to contemplate what kind of sermon series could possibly lead to increasing mainline birthrates.

What if there’s something else at play?

In his recent book, “The Righteous Mind,” moral psychologist Jonathan Haidt challenges the importance that institutions like mainline denominations place upon reason.

Likening reason to a tiny rider astride the far more powerful elephant of intuition, Haidt argues that reason functions mainly to convince ourselves of what we’re already feeling and doing.

Citing well-known studies, Haidt argues that liberals and conservatives are predisposed to see the world through partisan metanarratives. By nature, we marshal reason to highlight the facts that confirm our biases and ignore the facts that don’t fit.

All is not lost, though, Haidt writes. We can whisper to and guide these elephants of intuition. We just have to know how.

At the heart of Haidt’s analysis is his “moral foundations theory.” Viewing morality as akin to taste, Haidt articulates six major “flavors” of moral reasoning: care, liberty, fairness, loyalty, authority and sanctity. Haidt’s discovery: liberals rely on just three of these moral foundations (care, liberty and a limited understanding of fairness), while conservatives speak to all six.

Polarization occurs in part because liberals tend to have difficulty seeing how loyalty, authority and sanctity can even be articulated in ways that are moral. Haidt’s project is not to champion conservative views, however, but to encourage mutual understanding and to prod liberals to find ways of singing their song to reach a broader moral spectrum.

One of Haidt’s most intriguing points concerns people anthropologists refer to as WEIRD -- an acronym for Western, educated, industrialized, rich and democratic.

WEIRD people think in extremely narrow moral terms, mainly concerned with minimizing harm and maximizing liberty. In theological terms, WEIRDs are great at speaking about God’s love and talking about social justice but stutter when it comes to speaking to the other moral centers such as proportional fairness, loyalty, authority and sanctity.

Our academic seminaries are the epitome of WEIRD, and our pastors, yours truly included, are as WEIRD as they come. Our WEIRDness colors how we read Scripture, and it shapes how we preach.

Haidt’s data backs this up.

Haidt’s research team compared the language in sermons from liberal Unitarians with those from conservative Southern Baptists. Unitarian preachers made greater use of care and fairness words, while Baptist preachers favored words related to loyalty, authority and sanctity.

Bass and Chaves are correct -- mainline birthrate decline, along with other factors such as the erosion of trust in ecclesial leaders and the inability to retain youth, helped get us here.

But mainline leaders must reckon with Douthat and Haidt as well. Our theology matters, and the language we use to preach it matters, too.

Our music and message must change. We must learn how to reclaim profound moral foundations like loyalty, authority and sanctity and speak to them in our own voice.

Haidt’s understanding of loyalty refers to belonging to something larger than the self, implying that the self is not the measure of all things.

Martin Thielen’s WEIRD manifesto, “What’s the Least I Can Believe and Still Be a Christian?” while well-meaning, heads in the exact opposite direction. Thielen would lower the bar for membership to such a degree that joining the body of Christ no longer represents a death to self but is merely the voluntary act of the self, provided the church seems reasonable.

This watered-down approach offers no challenge to a culture insisting on individual rights, such as the right to assault-style weapons and armor-piercing bullets, no matter the cost.

Or take leadership.

Because of our distrust of authority, no WEIRD ever wants to be seen as an authoritarian leader. Yet, in “God’s Potters,” Jackson Carroll points out that while authoritarian leadership negatively correlates with congregational effectiveness, passive leadership designed to “empower” lay leaders likewise fails to produce good fruit.

Effective leadership, Carroll argues, blends a leader’s willingness to exercise authority with a leader’s ability to hear and learn from her congregation.

We’ve been singing for too long in too narrow a range. The ears of God’s people tingle for new octaves of moral depth.