Many researchers refer to psychedelic, religious, spiritual, and mystical experiences (PEs, REs, SEs, MEs) as if they are all distinct types of experiences. Given the many meanings of “religious,” “spiritual,” and “mystical” within Western cultures and the difficulties in translating these terms across cultures, it is clear that the meaning of REs, SEs, and MEs and their associated phenomenology varies depending on the context. In contrast, PEs have a relatively stable referent. Although researchers have operationalized and stabilized the meaning of MEs in various ways for scientific purposes, this approach blends the phenomenological features of experiences with the way they are interpreted. Distinguishing between phenomenological features and appraisals permits, investigation of the effect of RSM appraisals affect people’s response to the experience. As a relatively stable signifier, PEs allow researchers to investigate how the interplay between drug-induced phenomenology, mindset, and setting interacts to generate our experiences.