Book Review: The Religious Experience of Mankind. By Ninian Smart. Fontana, 1971. 735 pp. £2.10.; Fifty Key Words: Comparative Religion. By Eric J. Sharpe. Lutterworth Press, 1971. 81 pp. 65p.; The Buddha's Way. By H. Saddhatissa. George Allen & Unwin, 1971. 139 pp. £2.75.