Approximately 600 people from across Europe have officially joined Santo Daime, a Brazilian religion organized around the ingestion of a potent psychoactive beverage called ayahuasca. Santo Daime members (called fardados) regularly attend ceremonies where they imbibe ayahuasca while meditating, singing, and dancing for between 6 and 12 hours. Deeming ayahuasca a dangerous “hallucinogen,” most European governments have responded by arresting and prosecuting people who engage in Santo Daime rituals. Highlighting Belgium as a cultural bellwether of Europe, this dissertation pursues the following question: Residing within a social milieu that is dominated by secularism and mainstream Christianity, why are some Europeans adopting Santo Daime spiritual practices? The “secular” designates those aspects of social life that do not involve any recourse to supernatural entities. Through the latter half of the 20th century, most social scientists welcomed progressive secularization as an inevitable substitute for declining religions in Europe. Recently, a budding anthropology of secularism has emphasized how the institutionalization of materialist disenchantment tends to exclude alternative ideas about the nature of mind and reality. Conversions to transnational religions portend deeper shifts in how some Europeans are adapting to an increasingly interconnected world. The clarification of this process is important because scholars have yet to account for why some Westerners are making unorthodox religious choices in the age of secularization. During fieldwork, I asked informants why they had become fardados. The collective responses are summarized by one Belgian fardado who said: “Santo Daime is the key to a lot of solutions.” Fardados consider ayahuasca as a medicinal sacrament (or “entheogen”), which helps them to cure various maladies, such as depression, social anxiety, and alcohol/drug dependence. My informants’ understand their Daime practice as a form of mysticism, whereby the entheogenic ritual acts as a kind of introspective technology (what I term a “suiscope”). Empirical studies corroborate fardados’ claim that ayahuasca is benign and can be beneficial when employed in ritual contexts. One of the essential functions of anthropology is to render different cultural logics as mutually explicable. Accordingly, this dissertation endeavors to intercede in a misunderstanding between a secular hegemony and an unfamiliar religious subculture.