Both literary theory and biblical narrative criticism lack an articulate, comprehensive theory of character. Many Gospel critics perceive character in the Hebrew Bible (where characters can develop) to be radically different from that in ancient Greek literature (where characters are supposedly consistent ethical types). Most people also sharply distinguish between modern fiction and its psychological, individualistic approach to character and ancient characterization where character lacks personality or individuality. In Part I, we examine concepts of character in ancient Hebrew and Greek literature as well as modern fiction, arguing that although there are differences in characterization, these are differences in emphases rather than kind. It is better to speak of degrees of characterization along a continuum. In Part II, we develop a comprehensive theory of character in the Fourth Gospel, consisting of three aspects. First, we study character in text and context, using information in the text and other sources. Second, we analyze and classify the Johannine characters along three dimensions (complexity, development, inner life), and plot the resulting character on a continuum of degree of characterization (from agent to type to personality to individuality). We observe that many Johannine characters are more complex and round than has been believed so far. Third, we analyze and evaluate the characters' responses to Jesus in relation to the Fourth Evangelist's evaluative point of view, purpose and dualistic worldview.