This paper explores the question concerning the relationship between basic and higher layers of experience and self-experience. The latter distinction implicitly presupposes the idea of a univocal foundation. After explaining the formal ontological law of foundation, an attempt is made to clarify how the idea of foundation may be suitable to understand the relationship among moments, or layers, of self-experience. To this aim, the phenomenological descriptions of self- and world-experience in dementia and schizophrenia are compared. The comparison between these two, in many ways radically different, pathologies allows us to highlight both the potentialities and the limits of resorting to the foundational relationship for the description of lived experience. Taking the challenges coming from the description of dementia and schizophrenia into serious consideration, the meaning of the “stratified” account of self-experience will be eventually reassessed, and a way to complement the idea of foundation among layers will be proposed.