THE CHALLENGE OF OUR AGE, by Hendrik Hart; published by The Association for the Advancement of Christian Studies, Toronto, Ontario, Canada; 148 pp., $2.00 (paper). This book, written by the assistant professor of philosophy at the Institute for Christian Studies in Toronto, Canada, is part of the Christian Perspective Series and includes lectures given at the 1966 and 1967 Study Conferences of A.R.S.S. and F.C.U.C.