Reflection is a much-used concept in initial teacher training. By outlining the range of meanings found in the literature, the authors of this article take a critical look at this concept. At the same time, they identify a developmental but non-hierarchical vision of reflection, granting it the status of a metacompetence. A diagram is used to clarify the ecological and methodological dimensions of the thinking process. In this book, the author approaches critical reflection on the World through three different dimensions: The Dimension of Spiritualism; The Dimension of Idealism and ; The Dimension of Realism.This thirty-eighth book by Mr. BUGEME CHIRABA Jérôme, Professor and Senior Research Fellow, provides a detailed understanding of this critical reflection on the World, through a sociological analysis of these three dimensions.