chunk: The Doctrine of Virtue develops further Kant's ethical theory, which Kant first laid out in the Groundwork of the Metaphysics of Morals (1785). Kant particularly emphasizes treating humanity as an end in itself; in fact the Kant's retake of the second formulation of the categorical imperative (e.g. Groundwork of the Metaphysics of Morals) makes possible to deduce duties. The duties are analitically treated by Kant, who distinguishes: 1) duties towards ourselves; 2) duties towards others. The duties are: 1) perfect duties; 2) imperfect duties. Kant thinks imperfect duties let a latitudo: i.e., the possibility of choose maxims. The perfect duties instead do not let any latitudo and determine exactly the maxims of actions.