This is a new biography of the Founder of the Legion of Mary, one of the Catholic Church's most effective charitable agencies in the world today.

In the Legion of Mary, Duff built an organisation that depended on each member playing his or her part, rather than on any individual leader. Describing responsibility as 'the biggest tonic on earth', he believed in sharing responsibility, and warned against thinking that others cannot do things as well as we can ourselves.

The Legion of Mary is an organisation of lay Catholics dedicated to every form of social service and Catholic action for the welfare of the Church and of society. Duff's vision of a lay movement was revolutionary in its time and as recounted in this book explains why he faced so much opposition from Church authorities, especially in Ireland.

But Duff, who is on the path towards canonisation, exemplified the Catholic tradition of charitable work at its best - that you do not preach by lecturing but by works of mercy, compassion and unselfish altruism. This is an inspiring tale.

Finola Kennedy has been a Lecturer at University College Dublin and at the Institute of Public Administration, Ireland. She has served on a number of Boards, including the Housing Finance Agency (chairman), ACCBank and the Railway Procurement Agency. She was a member of the Review Group on the Constitution and the Commission on the Status of Women.

She is the author of the pioneering study, Cottage to Crèche: Family Change in Ireland (2001). She has contributed frequently to newspapers such as the Irish Times, the Sunday Business Post and the Sunday Independent.