Since the beginning of man's awareness of his language capabilities and language structure, he has assumed that speech is composed of discrete entities. The linguist attempts to establish a model of the workings of these distinctive sounds in a language. Utilizing an historical basis for discussion, this general survey of the distinctive feature principle illustrates the formation of the concept of these phonemic entities (the distinctive features) and their refinement and incorporation into structuralist and transformational-generative phonology. It is suggested that the development of the principle sheds light on the question of how a language utilizes sound matter, the adaptation and utilization of certain sounds in the workings of a language, as well as their representation in language models and theories. The phonological assumptions of Jakobson, Fant, Halle, Bloomfield, Chomsky, et.al. are discussed in an attempt to understand the concept of "sounds" as utilized by linguistic theory since its origin as a modern-day science. (Author/ CFM)