Sergio Bastianel s.j., born in 1944, is currently Ordinary professor of moral theology at the Pontifical Gregorian University in Rome and also serves as its academic Vice-rector. He spent his early years teaching and lecturing at the Pontifical Theological Faculty of San Luigi in Naples, Italy, and in later years he served as Dean of the Theological Faculty of the Pontifical Gregorian University. Among his publications are: Il carattere specifico della morale cristiana, 1975; Autonomia morale del credente, 1980; La preghiera nella vita morale, 1995 (translated into English: Prayer in...

Seyyed Hossein Nasr, currently professor of Islamic studies at the George Washington University in Washington D.C. is one of the foremost scholars of Islamic, religious, and comparative studies in the world today. Author of over fifty books and five hundred articles which have been translated into many languages, Nasr is a sought after speaker and often appears as an expert on radio and television programs. His career as a teacher and scholar spans over four decades.

Sidney Callahan, Ph.D, is an award winning author, professor and licensed psychologist. She earned her B.A. in English (magna cum laude) from Bryn Mawr College, her M.A. in Psychology from Sarah Lawrence College and a Ph.D in Social and Personality Psychology from the City University of New York. Callahan has written numerous articles, books, and columns devoted to religious, psychological, and ethical questions. She has been awarded many honors in the course of her career and served on many boards. For twenty years she taught and served as a tenured...

Dr. Siegmar Döpp is Professor of Classical Philology at the University of Göttingen.

Silvester Krcméry (1924 -2013) was a scout, a Slovak doctor, a political prisoner under communism and a Catholic dissident who, together with Vladimir Jukl, organized a large secret church in Slovakia. From 1951 to 1964 he was imprisoned. He was one of the organizers of the Candle Manifestation.

Siobhan Nash-Marshall holds the Mary T. Clark Chair of Christian Philosophy at Manhattanville College. She is the author of many academic books and articles on metaphysics – Participation and the Good: A Study in Boethian Metaphysics and Boethius's Influence on Theology and Metaphysics to the 1500s –and the problem of evil – most recently Free Will, Evil, and Saint Augustine and Evil, Pain, and the Problem of Properties – she has also written books and articles for the general public – Joan of Arc: A Spiritual Biography and What it Takes to be...