In Western countries conscientious objection is usually accommodated in various ways, at least in certain areas (military conscription, medicine) and to some extent. It appears to be regarded as fundamentally different from other kinds of objection. But why? This study argues that conscientious objection cannot be understood as long as conscience is misunderstood. The author provides a new interpretation of the historical development of expressions of conscience and thought on the subject, and offers a new approach to conscientious objection rooted in the symbol-approach to conscience.