Conspicuous in my title, the term 'source' is today highly problematic. Critics now understand 'source' variously and employ as well many different terms in its place. These terms, each one rich in its own embedded metaphors and critical implications, embody conflicting notions about what a source is and about how it functions. Our tacit acceptance of these conflicts has resulted in radical redefinition of sources and a revaluation of their relations to texts. To illustrate such changes, this essay will examine the critical history of Julius Caesar, a play that bears a close and complex relationship to a long-established specific source, North's Plutarch. The issues raised in this discussion should be pertinent, however, to less established sources, the tragedies of Seneca, let us say, and, of course, to other plays.

'Source', from the Old French 'sors', derives from 'sourdre', 'to rise or spring'. A source is a 'support'; 'the act of rising on the wing'; 'the fountain-head or origin of a river or stream'; 'the chief or prime cause of something of a non-material or abstract character'. A work of art then may rise from a source and leave it behind or it may flow from a source, existing in poised and dynamic tension, ever dependent on the source for its being. We often speak of tracing things to their sources, assuming then that there are connecting lines always present and discernible.