RELIGIOUS freedom, as it has been defined recently in domestic American affairs, is a cause that mostly attracts conservatives. Its heroes include Kim Davis, the Kentucky clerk who was jailed after refusing to authorise same-sex marriages, and Jack Phillips, the Colorado baker whose refusal to prepare a cake for a gay wedding is being mulled by the Supreme Court.

But in the last few days, the cause of liberty of conscience has acquired a champion who will appeal to the political left: Greta Lindecrantz. She is a 67-year-old woman who has gone to jail rather than give evidence in a case where her testimony might make a difference to whether a man is ultimately put to death. Her refusal is rooted in her Mennonite faith, and it follows prayerful deliberations with her church and pastor in Englewood, Colorado.

She was declared in contempt of court on February 26th after declining to answer questions from the prosecution in the case of Robert Ray. He is appealing against a death sentence imposed in 2009 for the killing of a witness who was due to testify against him in an earlier murder trial.

Mr Ray is arguing that his original defence lawyers were ineffective, a claim the prosecution wants to disprove. Ms Lindecrantz worked as an assistant to the original defence team, and the prosecution wanted to ask her questions about the team’s work.

Colorado’s Catholic bishops, despite their theological differences with the back-to-basics Mennonite creed, have backed Ms Lindecrantz. They have said she “should not be punished for her religious beliefs and convictions regarding the death penalty and the taking of human life.” The Catholic church opposes capital punishment, a stance which (along with its generous views on migration) appeals to liberals.

As for the Mennonites, they are difficult to place on any conservative-liberal continuum. Some of them are as culturally conservative as any person alive in the 21st century could be. But their detachment from earthly powers, and especially from the use of force by earthly powers, can make them progressive heroes.

In some ways, the stance of Ms Lindecrantz perfectly exemplifies the ethos of the Mennonites, a denomination with roots in medieval Germany that proclaims a return to the fundamental principles of the New Testament, which it believes to include an absolute rejection of violence.

Insofar as they are active in politics, it is generally in the cause of non-violence. Mennonites of the more wordly variety lobby the American and Canadian governments to reduce military spending, and they oppose the practice of executions in America and in all other countries. One of the most visible Mennonite initiatives consists of so-called Christian Peacemaker Teams who have won respect by trying to defuse tensions in hot spots like Colombia, Iraq and the West Bank.

But, as is explained by Royden Loewen, a professor of Mennonite studies at the University of Winnipeg in Canada, this is a religious movement which hesitates deeply before getting involved in any form of political or public affairs.

Its ranks include the Amish people, best-known as a farming community in Pennsylvania which retains the clothing, material culture and German dialect of pre-industrial central Europe. Also within the Mennonite fold are more “acculturated” members who lead conventional urban lives but are guided by what they regard as Biblical principles.

These include a rejection of infant baptism (that was the defining feature of the Anabaptist movement from which all Mennonites sprang) and a quietist but standoffish attitude to earthly authorities. It is an attitude which on one hand, accepts that earthly powers have been ordained by God, but also insists that Christians, as individuals or communities, shouldn’t have too much to do with those worldly institutions.

The professor, now 63, recalled that as a young Mennonite he applied for a job with Canada’s Department of Indian Affairs and immediately baulked when his employers asked him to swear an oath to Queen Elizabeth, Canada’s sovereign. Fortunately they were happy for him to make a simple affirmation of his intent to provide good service.

As for Ms Lindecrantz, one of the most unusual features of her story is the very fact she was acting as an assistant investigator for a legal defence team. For some Mennonites, acting in that role, however disinterested or noble the intention, would be an excessive entanglement with the powers and processes of this world.