A drug is a chemical substance that alters physiological or psychological functions, encompassing both therapeutic medications and psychoactive compounds. Authors like A.W. Duncan highlighted its role in modifying bodily processes, while Chas. A. Tyrrell cast doubt on its active nature, proposing that the body eliminates rather than responds to drugs.
Richard C. Cabot emphasized their effectiveness in treating specific conditions, contrasting with the 1911 Encyclopædia Britannica’s observation that drugs were often used synonymously with narcotics. These viewpoints underscore the dual nature of drugs as both curative tools and possible risks, illustrating their intricate categorization and societal control.