In his foreword to the treasure trove of prayer, Ancient Devotions to the Sacred Heart of Jesus by Carthusian Monks of the 14th-17th Centuries (revised and enlarged by Fr Peter Mary Joseph; Gracewing, 250pp, £12.99), Cardinal Sarah points out that Carthusian prayer “is anchored in interiority, solitude and silence”.

Monks in this austere order – described as never reformed because never deformed – developed their adoration of the Sacred Heart centuries before the apparitions of St Margaret Mary in 17th century France made it public and popular.