In light of Hobby Lobby and the surprising and welcome storming of the gates by gay marriage advocates in recent years, there seems to be quite a bit of talk about the virtue of tolerance. I'm not philosophically trained but much of it seems confused. The proximate causes of this post are this post by John Holbo and this post by Damon Linker. Both seem to be confused about the nature of the civic virtue of tolerance.
Tolerance has at least two facets of civic importance. First it lets people of somewhat differing moral values live together in peace. Second it fosters a humility about one's own beliefs that can be very useful if it turns out that some of those beliefs are wrong.
Tolerance has been fostered in Western societies in a few ways that I can identify, though I'd be happy to see more examples. First, we allow each other 'wrong' beliefs. This seems obvious, but in much of human history ostracism or forced re-education were the norm. Second, we allowed for a private and public sphere with differing levels of tolerance in each. This seems to have been undermined by drastically shrinking what counts as private dealings. Third we launder responsibility for violations of private moral judgments through the democratic allocation of taxing and spending functions of the government. So you may personally disagree with methadone treatment for opium, but as a society we've decided to do it. Your tax dollars will go toward it, but we won't force you to personally give methadone to patients if you disagree with it.
Linker's piece is a mess because he attacks the issue through the lens of intolerance as a form of bigotry. This obscures the methods and purposes of civic tolerance. Holbo's response is difficult because it treats all forms of democratic government action as equal in terms of their tolerance effects.
This is a essentially thinking aloud, but there are key differences between the government allowing something (not making it illegal), promoting it (usually by paying for it with tax dollars), and madating it (making citizens subject to penalties for not going along). Permitting something can allow for tolerance. Promoting it makes tolerance harder but not impossible. Mandating it makes tolerance tough.
By way of example, take the death penalty. The US federal government allows it. Certain state governments use tax dollars to engage in the death penalty. This is a source of contention for those who are against the death penalty and who then try to change the law. No one however is personally required to execute prisoners in violation of their moral normas (whether religiously derived or not). No US government body will take a doctor and force him to execute a prisoner. We tolerate dissent of the death penalty enough to allow people who disagree with it to avoid personally engaging in it. This is a good thing, and allows the political process to continue.
Part of the conservative pushback on 'toleration' is mere rhetoric to complain about losing the political contest on such issues. The gay marriage issue is such a case. No one is proposing that conservatives be involuntarily forced into a gay marriage. The government isn't particularly supporting gay marriage--there are a few tax breaks and a number of shortcuts through medical and estate planning. Many people don't like the idea of gay marriage, enough people do that it gets through in many places, and thats the political process for you. The virtue of tolerance comes in because you don't have to have a gay marriage yourself, nor associate with people who do (if you're an asshole--which lots of people are).
But some of the conservative pushback on toleration is well founded, and this is in the areas where the government goes beyond permitting or supporting, and into mandating. This is especially tricky as we approach the problem of services. The current progressive approach is to treat services exactly as we might treats goods (which is a bit ironic considering that many progressives would rail against the idea that workers are interchangeable widgets). The civic value of toleration suggests that whenever feasible we shouldn't force people to personally engage in a violation of their morals. We shouldn't force someone who is against the death penalty to kill a prisoner. We shouldn't force a doctor who opposes abortion to engage in a medically unnecessary abortion, or in a medically necessary abortion where another doctor is available without harm to the patient. Further we realize that entering the stream of commerce doesn't throw toleration to the wayside. If your housemaid strongly is against adultery, she should be able to quit if she finds evidence that you're cheating. Similarly a wedding planner should be able to quit if she finds out that your wedding involves two men. Hiring services isn't the same as selling groceries. There isn't any obvious reason why we should treat them identically. If you are a writer, and strongly support gay rights, you should be able to refuse a commission to write a reparative therapy tract.
We begin to get into serious problems when the government starts to mandate things instead of providing them. It sounds stupid to me, but it turns out that contraception is a hotly contested political issue. If enough people like me win in Congress, and we want to provide contraception, we should vote to spend tax dollars to do so. That allows tolerance for people who disagree, but lost in the political process. What we should not do is force people who (admittedly seem to me to have silly views) don't like contraception to actively engage in providing it. If enough people think the death penalty is a fair and good idea, the state should still not force pro-life doctors to kill criminals. What the current debate on tolerance seems to be missing is the idea that people seem to respond differently to having tax money allocated to things they don't like than they do when they are forced to engage more directly in things they think are morally wrong.