Philip Bosman explores the history of the word group from which the concept of conscience evolved. As a cognitive construct, the meaning of this ancient concept must be derived from the historical conceptual framework within which it features. As the modern term evolved from the Greek synoida word group, the author follows its history of development, from initial verbal phrases expressing an awareness of having done something wrong, to the later substantives referring to an inner entity monitoring the behaviour of the individual. Philo and Paul receive detailed attention because of the significant frequency and manner of usage in which the substantive forms of the word group appear in their writings.