The concept of conscience is analyzed here in two different ways: the systematic and the historical-literary. As to the first, systematic perspective, I distinguish (in part 1) three levels of conscience and on every level I identify two opposite categories (conscience that is ‛individual’ versus ‛collective’; ‛emotional’ versus ‛intellectual’; ‛motivating ex ante’ versus ‛evaluating ex post’). In the second, historical-literary perspective, I analyze two literary cases of fictional characters usually thought of as being guided or affected by conscience. The first case is the ancient Greek tragedy and here I offer (in part 2) a comment on the Sophoclean Antigone and the Euripidean Orestes presenting them both as dramas that contain an exemplary formulation of the phenomenon of conscience. Although Antigone and Orestes express their main principles of action in apparently different words, I suggest (in part 3) the two poetical visions of conscience are equally based upon a highly emotional behavior called pathos by the Greek. Thereby I provide a reason, why ancient philosophers created a new concept of conscience intended as an alternative to the poetical vision of human behavior. The new philosophical concept of conscience was based upon an axiological behavior called ethos. I also coin (in part 4) a concept of the ‛community of conscience’ where I distinguish four ‛aspects of solidarity’ in conscience, namely, somebody’s own self, a group of significant persons, a group of the same moral principles, and a sameness of life. In the end I turn (in part 5) to a historical-literary case in Joseph Conrad’s last novel The Rover (1923), which provoked a lively discussion among Polish authors and seems useful as an illustration of several levels of ‛solidarity of conscience’.