Magic
Magic (Greek mageía) is the symbolic-ritual practice of intentional influence on reality through actions whose effect is not explained by ordinary causality. Includes ceremonial magic (Hermetic, Cabalistic), natural magic (herbs, stones), sympathetic magic (image, name), and more. Classified into "white" (benevolent) and "black" (harmful) — a popular distinction, not always sharp in original tradition.
Modern theories
Aleister Crowley (1875-1947) defined magic as "the science and art of causing change to occur in conformity with will." Anthropologists (Frazer, Malinowski, Mauss) studied magic as universal social phenomenon.