Abstract

This paper tries to reconstruct the origin and the main developmental steps of our concept of conscience from antiquity to the middle Ages. My thesis is, that in antiquity above all the Sophistic movement, the tragic poetry of the Greeks and the forensic rhetoric of the Romans delivered the material for philosophical reflection on the phenomenon. A first systematic result of this reflection can be found in hellenistic philosophy, above all in the stoic theory of oikeiōsis. It reached the summit of philosophical strength and precision within the Christian era in the theory of Thomas Aquinas, who combined platonic, aristotelian, stoic and genuinly christian traditions. He determines conscience as a matter of reason, judging our own and only our own past, present and intended future actions, and distinguishes between ‚Synderesis‘ as habitus principiorum, without error, and ‚Conscientia‘ as actus applicationis, error-prone, but absolutely binding.