Of all the Pandora's boxes governments are loath to open, the funding of religious education is right near the top of the list. However dated the status quo may be, messing with it is a guaranteed recipe for enraging voters.

But then, Ontario's Premier - normally as pragmatic as they get - has this week earned himself the wrath of Muslims and Orthodox Jews alike by taking a surprisingly bold stance against Sharia law, and in turn all forms of state-sanctioned religious arbitration. So perhaps we can indulge ourselves, and fantasize that Dalton McGuinty will one day tackle the bizarrely inequitable structure of Ontario's public education system.

"No responsible person disputes that explicit legally entrenched religious discrimination in open violation of basic international human rights law is unacceptable in today's multicultural Ontario," Toronto lawyer Noam Goodman wrote in these pages on Wednesday. Mr. Goodman's complaint, shared by protesters who picketed Mr. McGuinty's appearance at a B'nai Brith human rights dinner later that day, is that Canada's largest province continues to fund Catholic schools to the exclusion of other religions. The constitution's "worthy" protection of cultural diversity through education funding to "significant religious minority groups," he wrote, "has not been updated to reflect Ontario's current multicultural demographic."

If his prescription is the wrong one (see below), Mr. Goodman's diagnosis is on-target. That Ontario currently has two separate public school systems, one for Catholics and one for the rest, is an anachronism dating back to Confederation - a time when Catholics faced rampant discrimination, and public schools were Protestant, rather than non-denominational.

That Catholic school funding was only extended to the final years of high school by outgoing premier Bill Davis in the mid-1980s - either as a sop to Catholic voters, a well-intentioned grand gesture before his retirement, the product of his friendship with Emmett Cardinal Carter or some combination thereof - is beside the point. Considering that Catholic schools were already funded through Grade 10, Mr. Davis was mostly fixing a messy process in which kids risked being dumped out of one system and into another for their last few years of school - and, of course, trying to live up to Ontario's constitutional commitment to a Catholic system, which is what it all comes back to.

There are very, very few cases in which opening up the constitution is smart. But the Catholic school requirement has already proven an exception to the rule, with both Quebec and Newfoundland making the decision themselves to do away with the dual systems - as the Constitution allows in cases where provisions solely affect one province - and no apocalyptic scenarios unfolding. Provided that the federal government chose not to go out of its way to block it, Ontario could shift to a single public system as well.

Understandably, none of Ontario's parties are keen to go anywhere near a reform that would produce an extremely vocal outcry. But if merely doing the right thing isn't incentive enough, they'd do well to consider that there is only one other fair option - the one that's favoured by Mr. Goodman and many others.

If one major religious group is allowed to have its own publicly funded schools, those interests rightly contend, it's only reasonable that others should have the same privilege. It's an argument that Mike Harris's Conservatives partially bought into, establishing a tax credit for parents paying for their kids' religious education. If the Tories hadn't made the strategic mistake of simultaneously trying to advance their own ideological interests by applying that rebate to non-religious private schools as well, allowing their successors to do away with the legislation with ample public support, that policy would still be on the books. But a more narrowly applied tax credit for denominational schools would probably find favour so long as the Catholic system exists. And many religious education advocates, Mr. Goodman included, would like to go much further by creating full public school boards for other religions.

Suffice it to say that not all fair solutions are created equal. While establishing a broad array of religious public school boards would eliminate the current discriminatory scheme, it would also carry enormous social consequences. Rather than growing up in the pluralistic society that exists around them, kids would be exposed to a narrow range of cultural backgrounds and perspectives.

It's not just secular liberals who should fret this scenario. For those who fear that the downside of multiculturalism is a failure of minority groups to integrate into mainstream society, the notion of segregating kids by religion should be terrifying.

It's not an imminent development. But sooner or later, publicly funded religious education will have to be viewed as an all or nothing proposition. As it did on religious arbitration, Ontario's government would do better to choose the latter.