Alchemy is a philosophical and protoscientific tradition practiced throughout Europe, Africa and Asia. It aimed to purify, mature, and perfect certain objects. Common aims were chrysopoeia, the transmutation of "base metals" (e.g., lead) into "noble metals" (particularly gold); the creation of an elixir of immortality; the creation of panaceas able to cure any disease; and the development of an alkahest, a universal solvent. The perfection of the human body and soul was thought to permit or result from the alchemical magnum opus and, in the Hellenistic and western tradition, the achievement of gnosis. In Europe, the creation of a philosopher's stone was variously connected with all of these projects.
In English, the term is often limited to descriptions of European alchemy, but similar practices existed in the Far East, the Indian subcontinent, and the Muslim world. In Europe, following the 12th-century Renaissance produced by the translation of Islamic works on science and the Recovery of Aristotle, alchemists played a significant role in early modern science (particularly chemistry and medicine). Islamic and European alchemists developed a structure of basic laboratory techniques, theory, terminology, and experimental method, some of which are still in use today. However, they continued antiquity's belief in four elements and guarded their work in secrecy including cyphers and cryptic symbolism. Their work was guided by Hermetic principles related to magic, mythology, and religion.
Modern discussions of alchemy are generally split into an examination of its exoteric practical applications and its esoteric spiritual aspects, despite the arguments of scholars like Holmyard and von Franz that they should be understood as complementary. The former is pursued by historians of the physical sciences who examine the subject in terms of early chemistry, medicine, and charlatanism, and the philosophical and religious contexts in which these events occurred. The latter interests historians of esotericism, psychologists, and some philosophers and spiritualists. The subject has also made an ongoing impact on literature and the arts. Despite this split, which von Franz believes has existed since the Western traditions' origin in a mix of Greek philosophy that was mixed with Egyptian and Mesopotamian technology, numerous sources have stressed an integration of esoteric and exoteric approaches to alchemy as far back as Pseudo-Democritus's first-century AD On Physical and Mystical Matters (Greek: Physika kai Mystika).