WHEN GOVERNMENT actions are challenged, we too often get a knee-jerk response, with officials defending the government, or their little piece of it.

That’s the type of thinking that leads, for instance, to the state spending millions to fight a lawsuit that charges that we’re not providing an adequate education for all children — a question that might be a close call from a constitutional perspective but that isn’t even debatable from a perspective of what is true and what isn’t. It’s the type of thinking that sometimes leads prosecutors to pursue “victory” in court at all costs — and forget that their job is to try to discover the truth and seek justice, even if that means fewer convictions.

That’s why it was so refreshing to see Attorney General Henry McMaster take the bold step of refusing to defend those in state government who believe the hodgepodge of legislation patched together under the name Life Sciences Act meets constitutional standards. Instead, while the Legislature tries to defend its actions, Mr. McMaster will go to court on behalf of the state of South Carolina and agree with a Greenville plaintiff who says the legislation violates the constitutional requirement that a bill must relate to a single topic.

The move is not without risk. Legislators immediately suggested that Mr. McMaster was trying to latch onto the immense popularity of Gov. Mark Sanford, who vetoed the Life Sciences Act and threatened to sue the Legislature after lawmakers handily overrode his veto. (He ultimately backed down, but a self-styled government watchdog took up the cause.) It was as if some legislators couldn’t even comprehend that an attorney general might take such a position simply because he believed that was his duty. If the Legislature prevails, lawmakers will no doubt hammer hard at this idea that Mr. McMaster’s actions were driven by politics, not an honest assessment of the case.

Moreover, his point is easy to miss. The Associated Press initially topped its article on Mr. McMaster’s decision with this headline: “McMaster sides against state in lawsuit over Life Sciences Act.” The headline was quickly changed, likely after Mr. McMaster corrected that all-too-common misperception. As he explained: “It is clearly the attorney general’s duty to defend the state, but that means defending the constitution. Statutes come and go. The constitution is the heart of what the state is, and that’s what we have to defend.”

The case is not as straightforward as it appears. There’s no doubt that the Life Sciences Act deals with more than one topic — it creates four-year programs at two colleges, changes LIFE scholarship requirements, funds a convention center, offers tax incentives to pharmaceutical companies, creates a state-run venture capital fund and lets colleges borrow more money. The framers of the constitution prohibited such laws because they know that tacking unrelated amendments onto bills can easily result in legislators being duped into passing laws they didn’t notice and the public being shut out of the lawmaking process.

The question is whether previous Supreme Court rulings — which have historically been highly deferential to the Legislature, which appoints judges — leave enough room to stretch the clear meaning of words this far. But whether Mr. McMaster prevails or not, we should all be proud of the fact that the official position of our state — not of our Legislature, but of our state — is in opposition to the anti-democratic, unaccountable and sometimes dangerous practice of bobtailing.