THE SUPREME court on Tuesday will devote a double session to hear arguments on one of the most contentious pieces of the Affordable Care Act : the rule that companies providing health-care insurance to their employees include coverage for a range of contraception services. Two firms — Hobby Lobby and Conestoga Wood — contend that complying with the law would violate their owners’ religious principles, so the Religious Freedom Restoration Act (RFRA) demands that the government grant the companies an exception from the rule. We think the firms are wrong.

Congress has wide authority to regulate the public marketplace; that shouldn’t be at issue. But how much did Congress limit itself when it said, in RFRA, that a person’s religious practices can be “substantially burdened” only when doing so is critical to pursuing a “compelling governmental interest?”

The government and its supporters argue that this case doesn’t require the court even to get to that question. Even if corporations’ or their owners’ religious rights are implicated here — big ifs — no one’s religious practices are being burdened to a “substantial” degree. Neither the companies nor their proprietors are involved in the decision of any employee to obtain or use the birth control methods to which they object, and there is no net insurance cost to providing unfettered access to birth control, since unintended pregnancies are expensive.

That would be good enough for us to throw these cases out. But let’s assume the court moves past these arguments and addresses the question of what legal protections Congress meant to confer on corporation owners via RFRA. It ought to find that the governmental interest in advancing its contraception rule is “compelling,” and that its means are reasonable. Like it or not, most Americans with private insurance get it through their employers . Congress did not blow up this system as it reformed the health-insurance industry. Rather, lawmakers were obliged to work within and around it to accomplish a variety of worthy public health goals.

One goal was to provide adequate coverage to women. A panel of independent experts — not liberal ideologues in Congress — determined that assuring access to a range of birth control products to all women, not just those who could afford it, would convey major public health benefits. It’s true that some non-compliant plans here and there were grandfathered in — but they will phase out, making the rule comprehensive.

Under U.S. law, corporations get substantial privileges, such as limits on owners’ financial liability. Now, they have been asked to take on responsibilities, such as providing decent health-care coverage, with the aid of massive tax subsidies. Not every American of every creed will be comfortable with reasonable, general rules that extend across the marketplace — requiring vaccinations, say, or prohibiting discrimination against women in the workplace. But it’s not feasible for a corporation to easily opt out of any generally beneficial law that happens to offend its owners. That is a principle vital to maintaining a functional, pluralistic democracy.