 The holism of Mulla Sadra’s approach may be seen in his examination of eschatology. One of the key points of contention in mediaeval Islamic thought concerned the possibility of metempsychosis, an idea that had permeated through the Neo-pythagoreanising Neoplatonism of Late Antiquity into Islam. Previous Islamic philosophers had even demonstrated some sympathy with the idea. But Mulla Sadra, consistent with the tradition of Avicenna, rejected the notion as inimical to his vision of the nature of the soul, its pre-existence, its faculties and its afterlife. Before criticising metempsychosis, Mulla Sadra argued that a proper understanding of the principles of his philosophical method will make clear his objection to the idea. In a number of works, he sets out eleven principles of his method that show the relevance of metaphysics to psychology and eschatology. In the relevant section of the Four Journeys, Mulla Sadra (2001–5, IX: 261–72) describes these eleven principles: