The battles for Lourdes lifted ladies to higher planes

Lourdes presents a formidable challenge to anyone seeking objective analysis. As a shrine, and later as a centre of cult and pilgrimage, it would assume great symbolic significance, dividing the Catholic faithful even as it invited outrage from anti-clericals and republicans.

With equal fervour historians have ranged themselves either on the side of science and progress - a matter of deep conviction for many in the later 19th century - or of faith and the miraculous. Thus Notre Dame de Lourdes by the journalist Henri Lasserre captivated the Catholic world when it was published in 1869, selling more than a million copies by 1900, while agnostics sought solace in the secular attacks of Emile Zola and the dismissive tirades of medical opinion. There can be, it might seem, no middle way in a minefield of contradiction and partnership.

Yet it is this path that Ruth Harris has chosen to tread, picking her way gingerly between the claims of Catholic apologists and the disclaimers of anti-clericals as she struggles to extricate fact from propaganda. Her own intellectual background, she tells us, can be traced to Jewish secularism, while her most recent research was in the history of 19th-century French medicine. In researching this book she had, quite consciously, to suspend her disbelief. She listened to the accounts of pilgrims and believers, joining one of the pilgrimages of the sick and disabled as a volunteer helper, participating in the many processions and religious services, the prayers for intercession and the curative baths. She may not have gained faith in the process, but she did gain a greater understanding of the mentality of the faithful and an admiration for the selflessness of the nuns and nurses of Lourdes.

The result is a highly readable and deeply learned book that draws on the work of modern anthropologists and social theorists as well as on more conventional historical sources, and that is lavishly and very tellingly illustrated. It is also a complex and multi-layered study that lurches quite dramatically between very different discourses on Lourdes and on the uses that were made of the shrine as it was systematically exploited and commercialised by others.

The book starts by retelling, very simply and movingly, the story of the 14-year-old shepherdess and of the 18 apparitions that she reported seeing at the grotto of Massabielle in 1858. Bernadette Soubirous was, like many Christian visionaries of the 19th century, young and poor, endowed with a certain rustic simplicity. The vision that repeatedly appeared to her as she was drawn back to the grotto, despite the admonishments of all around, she described as "small" and "white", qualities that Harris links to the traditional "white ladies" of Pyrenean folklore. Over months, the vision came to be identified as the Virgin Mary - "I am," she confided to Bernadette, "the Immaculate Conception" - and she ordered her to scrape in the mud with her hands at a spot that then gave life to a spring of water.

Something miraculous had occurred, something that deeply embarrassed many Catholic intellectuals as Bernadette's grotto began to attract large crowds of curious onlookers. It was the intervention of the Catholic polemicist Louis Veuillot and the populist involvement of the Assumptionist order that subsequently transformed this simple shrine into a major business with, at its core, healing by faith, the baths and ceremony of immersion, the curing of the sick where humanist medicine had failed. Bernadette herself became a peripheral figure, dispatched to a convent in Nevers where she would die of consumption in 1878.

Much of what follows is about politics: the politics of the French state and of medical professionalism as much as the politics of the Catholic church. It is not easy to remain sympathetic to the Assumptionists when they linked their spirituality to anti-Semitism and to blistering attacks on the Third Republic, or when Lourdes became part of a polemic against rationalism and medical science.

In places, Harris allows herself to express that irritation, but she is careful not to condemn the Marian cult and writes with genuine sympathy of the pilgrims who travelled in hope of finding miracle cures, of the trainloads of the terminally ill that descend on Lourdes every year from the Catholic heartlands of rural France. Nor does Harris dismiss out of hand claims that there were cures, which were monitored and investigated by the sanctuary physicians when in 1883 they established the Bureau des Constatations Médicales at the shrine.

Above all, Harris sees in Lourdes a fascinating case study in female empowerment through religious faith and through the care offered by nuns and female carers, the channelling of women's aspirations into spiritual and charitable achievement at a time when they remained largely excluded from the public sphere.

Alan Forrest is professor of history, University of York.