The article undertakes a critical analysis of Adorno's interpretation of Kant's conception of practical freedom, with the primary aim of investigating the key concept of 'addendum' proposed in the third part of Negative Dialectics, Model Freedom. We commence by presenting some central aspects of Adorno's conception of human freedom, thereby directing the argumentation towards defending the hypothesis of a certain artificiality inherent in the concept of an addendum. This consideration arises from the somewhat antinomian and generic manner in which Adorno addresses the relationship between the realms of thought (consciousness, language, culture) and nature (body, physiology, natural impulses).