A Maine state trooper follows Kaci Hickox and her boyfriend on their bike ride. (Robert F. Bukaty/AP)

Kaci Hickox will not be caged.

The nurse who protested her detainment in a New Jersey tent upon her return from treating Ebola patients in West Africa is now defying a state-imposed home quarantine in Maine. Physically healthy, Hickox and her boyfriend went for a bike ride Thursday morning, taking both state troopers and a small army of reporters on a tour of New England's beautiful fall foliage on a brisk late-October morning.

As casual bike rides go, this trip was as defiant as they come. For the 33-year-old Doctors Without Borders nurse, it was a ride for science, and for civil liberties. At the heart of her protest is a belief that authorities in the two states were confining her out of fear–both political and irrational–rather than medicine. She has no fever and feels fine, and as public health officials have stressed repeatedly in recent weeks, Ebola can't be transmitted unless a person is symptomatic.

She told reporters that she wouldn't "stand here and have my civil rights violated."

"I'm fighting for something other than myself," Hickox said at one point, according to ABC.

Hickox generated enormous public sympathy during the weekend she spent locked in a tent outside a hospital in Newark; the conditions drew rebuke from federal public health officials and even the White House, prompting President Obama to literally as well as rhetorically wrap his arms around U.S. health-worker "heroes" who are fighting the Ebola outbreak in West Africa.

But a quarantine in the comfort of one's home is not the same as confinement to a hospital tent. By all accounts, Hickox will not lose money or professional status by kicking it for another two weeks in her modest rural cottage in Fort Kent. Is she simply being unreasonable?

Governor Paul LePage certainly thinks so. A Republican who is facing voters in a tight re-election campaign next week, he said in a statement Thursday afternoon that after negotiations with Hickox failed, he would "exercise the full extent of his authority" under the law to enforce her quarantine. LePage wouldn't say exactly what that entailed, but presumably it could begin with a court order allowing the police to prevent her from leaving her home. The statement from his office said officials had discussed an arrangement that would allow Hickox to go for walks, runs, or bicycle rides as long as she stayed away from the public. "Unfortunately, an agreement was not reached," the statement said.

Hickox has retained noted civil rights attorney Norman Siegel, and they could be headed to court. Her plight has become a proxy for the battle raging between federal health officials on the one hand, who are trying to prevent an overreaction to Ebola, and state and local authorities, who are responding to the anxiety—rational or not—of their constituents.

"As a policy matter, it's legitimate to deprive people of liberty because of contagion," Jay Stanley, a senior policy analyst at the American Civil Liberties Union, said over the phone on Thursday. "It's not legitimate to deprive people of liberty because of mob fear."

Constitutional scholars on Thursday said it was unclear how a judge would rule. "Courts have generally sided with public-health authorities, but public-health authorities have generally had science on their side, and that may not be the case here," said Michael Dorf, a constitutional-law professor at Cornell University Law School. "It's just impossible to know what a court would do with it."

Lawrence Gostin, an expert on global-health law at Georgetown University who has corresponded with Hickox in recent days, called her confinement "an overreach" and encouraged her to fight it. "It's unlawful and unethical," he said in an interview. Gostin was less certain, however, on the question of whether Hickox's bike ride was a wise and principled move, or an unnecessary provocation. "I don't want to judge her," he began. "If it were me, I would probably comply with it, but challenge it, in a quiet and dignified way."

But he said Hickox was broadly waging an important fight against policies that are not based on science and are fanning fears that aren't justified. "We need to really get a grip here," Gostin concluded.