This book gathers a series of lectures written by Schrödinger in the years 1940-1955, and also a well-known letter to Eddington of March 22, 1940. – The selected texts bear on the interpretation of quantum mechanics, as well as on philosophical issues about quantum mechanics. Their interest is that they correspond to a distinct phase of Schrödinger’s reflection. During the 1940s and the 1950s, while he was working at the Dublin Institute of Advanced Studies, Schrödinger abandoned the predominantly sceptical stance he had adopted during the 1930s, about the then dominant Copenhagen interpretation of quantum mechanics, and became much more assertive. Two insights allowed this renewal of Schrödinger’s reflection on quantum theory. The first insight is his radical critique of the concept of a material corpuscle, of its individuality, of its permanence, and of its so-called « properties ». The second insight is the growing importance of Quantum Field Theory and the possibility Schrödinger saw of interpreting the formalism of Second Quantization in terms of vibration eigenmodes of the universe as a whole. – Another crucial element of this new cluster of ideas Schrödinger was defending at that time, is a metaphysical construal of the concept of « reality » adumbrated in his project of William James Lectures of 1954. According to him, « Reality » is but a construct made out of a set of phenomenal perpectives, united in an invariant structure. Schrödinger then felt confident that it is possible to recast the whole ontological scheme of physics, in view of the enlarged set of phenomenal perspectives that is made available by advances in experimental research, and also in view of the new types of invariants that arise from it. This being granted, one can accept that the basic entities are no longer « particles », but (say) state vectors in the Fock space of Quantum Field Theory. – Introduction; – 1. July 1952 Colloquium; – 2. Transformation and interpretation in quantum mechanics (c. 1952); – 3. Notes for 1949 seminar; – 4. Notes for 1955 seminar; – 5. From a letter to Arthur S. Eddington, March 22nd 1940; – 6. William James Lectures. M.-M. V.