It must also be considered that there are a wealth of different exceptional experiences that people may have whilst on these substances; in this regard there is a lot to be learned from the lineage of shamans who have been using these substances for millennia and who are well practiced in navigating the altered states they produce. From direct research and from the literature, it seems that most every type of transpersonal experience can be had under the influence of psychedelics (e.g., Grof, 2001; Luke & Kittenis, 2005) and these may teach us something about the phenomena that are ordinarily studied in psychical research. For instance, the apparent contact with discarnate entities, particularly under the influence of one of the body’s naturally occurring psychedelics, DMT, can inform studies into mediumship, apparitions, sleep paralysis, and alien abduction experiences (Luke, in press). However, the multitude of these complex experiences means that a taxonomic approach is also required so that we can ultimately determine which substances, under which environmental conditions and for which people, best activate a particular sort of experience; that is, what experiences arise out of a combination of set, setting, and substance? That is a lot of factors and a lot of questions to ask, so you see that this is a completely nascent field of study, and we are wise to admit that currently we know virtually nothing.