Since the immanence of life to matter excludes dualism, this chapter explains perception as the genesis of the subject through the display of a world reflecting its possible actions. Going against the sacrosanct view of realism and idealism making perception into a projection of subjective images and, by extension, against the phenomenological thesis of intentionality, Bergson advances the bold thesis that things are perceived where they are, and not in the brain or the mind. This means that perception is just selection and that the role of the brain is to retard the reactions of the body to selected stimuli. Hence the distinction between pure and concrete perception: it means that the selected portion develops into images as a result of the intervention of memory.