Many political theorists, pundits and even presidential candidates have advocated some variation on the claim that religious and secular reasons have a differential justificatory potential: at least some kinds of secular reason, but no kinds of religious reason, suffice to justify coercive laws in a pluralistic democracy. Jurgen Habermas articulates a distinctive version of this claim in his recent paper, “Religion in the Public Sphere.” Although his treatment of the obligations of citizenship as they bear on the justificatory role of religious reasons is refreshingly evenhanded, he adopts familiar restrictions on the justificatory role of religious reasons in formal political institutions – even going so far as to claim that “the standing rules of procedure” in parliament must “empower the house leader to have religious statements and justifications expunged from the minutes.” I understand Habermas to be of the view that these standing rules would apply to religious reasons generally, but not to secular reasons generally – a sign that the justificatory status of religious and secular reasons is unequal indeed.

I disagree with this differential treatment of the religious and the secular — not only Habermas’ particular formulation, but any position relevantly like it. I favor an alternative understanding of the moral expectations those already committed to liberal democracy reasonably have regarding the role of religious reasons in justifying political coercion. According to that alternative understanding, religious and secular reasons have exactly the same role to play in justifying coercion, whether in the political decision-making of ordinary citizens or in the public advocacy of the members of the legislature. I briefly sketch that position below.

For a number of fairly obvious reasons, it would be a morally terrific thing if each and every citizen in a liberal polity had what each regards as adequate reason to support each piece of legislation to which she is subject. Each citizen and legislator therefore has some reason to try to approximate that ideal state and so has some reason to abide what I prefer to call an ideal of conscientious engagement. This ideal has roughly two analytically – not temporally — distinct components.

First, citizens and legislators should do their best to determine which of the feasible political options before them is morally best, and then they should support the very policy they responsibly believe to be morally best. When they do so, they should employ the epistemic resources available to them, and they may do so by relying on any of the truths they responsibly take to bear on the matter at hand. So if I am a secularist who believes that some version of utilitarianism is the sober moral truth, then I have all the reason I need to employ my utilitarian convictions to determine which of the policy options before me maximizes the relevant goods. In that case, my support for some legislation might properly depend on a rationale I know that many of my compatriots properly reject. A comparable point applies forthwith to other believers, whether Christian, Wiccan, Hindu, Kantian and whatever. (It should go without saying that I cannot do the best I can to determine which policy option is morally best without listening to my compatriots, learning from them and, in particular, opening up my political convictions to their critical scrutiny.)

Second, citizens and legislators should do their best to persuade their compatriots to support the policies they take to be morally best. In my view, respect for their compatriots as having great and equal worth requires citizens and legislators to do what they can to approximate the ideal state of affairs in which all have what each regards as adequate reason for the laws all must obey. With respect to some of my compatriots, this will involve articulating the arguments that actually persuade me: hopefully some others will be persuaded by the arguments that I actually find persuasive. But for those who have fundamentally different normative commitments, the arguments that convince me will ring hollow. And in that case, I have to exit from my parochial point of view, see how things look as others see them, and then do my level best to articulate reasons that persuade them: to the secular utilitarian, I can try to show that my favored policy maximizes net value; to the Conservative Protestant I can appeal to the Bible; to the Muslim the Koran; to the Catholic, church authority or natural law. Of course, when I exit from my parochial point of view, I do not thereby aspire to some common, shared, accessible, public or universal perspective. I exit from my point of view into the equally parochial perspective of the person(s) whom I hope to persuade. In some cases, I will be able to articulate one argument that is able to persuade those who inhabit importantly different worldviews, and in that case I will be able to articulate a rather more ecumenical argument. I might have pragmatic reason to do so, but so far as I can tell, I have no better moral reason to articulate one argument that persuades three people than three distinct arguments that persuade the same three.

So I should form my political commitments as best I can given my epistemic resources, listen to others and revise my commitments in light of what they say, try to persuade others by appealing to their commitments and hopefully get them to see matters my way. Moreover, I should expect my compatriots to return the favor: they should form their political commitments as best they can given their epistemic resources, they should listen to me and revise their commitments in light of what I say, they should try to persuade me by appealing to my commitments and hopefully get me to see things their way. In so doing each of us strives to maximize the number of people who support the policies they believe in good conscience to be morally correct.

But of course, in the real world, we seldom reach consensus as to why the laws that govern us are appropriate and we seldom reach convergence on the laws to which we must submit. We disagree about both what and why. No matter how assiduously we strive to articulate arguments that persuade others that our favored policies are correct, there will always be some epistemically competent and morally sensitive peers who are utterly unpersuaded – and rightly so given their noetic endowment. That is the cost of living in a pluralistic liberal polity. Disagreement is endemic and ineradicable. Moreover, at some point the conversation has to stop and we have to make a collective decision about what to do. Forced choices are unavoidable. Faced with such forced and contentious choices, each of us should act as conscience dictates, with the result that some of us win and some lose. The cost of living in a pluralistic society is that some of us will inevitably be subject to laws we take ourselves to have adequate reason to reject. This is how it has been, is now, and ever will be.

Now the ideal of conscientious engagement mentions nothing in particular about the justificatory role of religious reasons in liberal politics. It’s a general position that applies to religious and secular reasons, political decision-making and advocacy, citizens and legislators. But its implications for that topic are not difficult to draw out. I’ll mention two and then draw a general conclusion.

First, the ideal of conscientious engagement requires citizens and legislators to do their level best to articulate some rationale that their compatriots find persuasive, and because a pluralistic society will inevitably include some secularists, it follows that those who support some policy on religious grounds must do what they can to articulate some secular rationale for that policy. So religious citizens and legislators must attempt to articulate secular reasons for their favored policies. Or, to adopt one of Jurgen Habermas’s suggestions, religious citizens and legislators may rely on others to translate their religious arguments into some secular equivalent. Note, though, that what’s good for the religious goose is equally fine for the secular gander. If secularists support some policy to which their compatriots have religious objections, then secularists have an obligation to exit their parochial perspective, inhabit the mindset of their religious compatriots, and do what they can to persuade their religious compatriots to support their favored policy. Of course, I am assuming here that for a secularist to provide a religious believer with a secular rationale need not be for the secularist to provide the believer with any reason that should persuade, or that is even accessible to, the believer. This assumption seems correct: the secular is not the locus of the universal, the common or the accessible any more than the religious is of the particular, the parochial or the sectarian.

Second, although the ideal of conscientious engagement requires citizens and legislators to strive to persuade their compatriots, it recognizes that those aspirations will sometimes meet with failure, and it permits them to support laws for which some of their compatriots lack what their compatriots regard as an adequate rationale. This general claim applies to religiously grounded laws: it’s possible in principle that citizens and legislators support some law for which they have an exclusively religious rationale even though they fully comply with the ideal of conscientious engagement, and hence it’s possible that they permissibly pass some law that has only a religious rationale. This possibility is, so far as I can tell, politically unlikely in the liberal polity with which I am most familiar, viz., the United States, where any law that is passed must, as a practical matter, have the support of no doubt a variety of secular reasons. Nevertheless, it is a logical possibility and should it be realized, nothing morally wrong need have been done: a law which lacks adequate secular support need not be morally defective in any respect. Of course, a comparable point applies to laws that are unpersuasive to religious believers: it’s logically possible though politically infeasible that citizens and legislators pass some law that lacks any rationale that’s persuasive to certain religious believers and such a law would not necessarily be morally defective in any respect.

These two implications of the ideal of conscientious engagement for the proper political role of religious reasons exemplify an important principle: not only does the ideal of conscientious engagement treat religious and secular reasons equally, any normative constraint that applies to the reasons on the basis of which we make political decisions or advocate for our favored policies must apply impartially to religious and secular reasons. Pace Habermas, this impartial treatment of the religious and secular applies not only to citizens, but also to legislators engaged in the work of the legislative branch of government. Equal treatment of religious and secular reasons is the order of the day, whether in the halls of Congress or around the dinner table: religious believers have no more, and no less, a responsibility to aspire to persuade their secular compatriots than secularists have an obligation to aspire to persuade their religious compatriots; if laws that lack a plausible religious rationale are permissible, then so are laws that lack a plausible secular rationale; if secularists may support laws solely on the basis of reasons that fail to persuade religious believers, then so also may religious believers support laws solely on the basis of reasons that fail to persuade secularists.