This treatise on the theoretical and historical foundations of distinctive feature theory traces the evolution of the distinctive features concept in the context of related notions current in linguistic theory, discusses the evolution of individual distinctive features, and criticizes certain acoustic and perceptual correlates attributed to these features during development of the theory. The concepts of opposition, neutralization, archiphonemes, and markedness are treated, and the relationship of the distinctive feature concept to phonetics, phonology, binarity, and feature hierarchy is discussed. The feature system of Trubetzkoy is compared with earlier classifications and with systems developed by Chomsky, Halle, Fant, and Jakobson. A bibliography is appended. (JB)