The ethical justification, not the juridic legitimacy of trading in art and cultural property is explored. The reflection is limited to matters of principle, the major aim being to erect a normative basis providing criteria and arguments for the debate concerning our dealing with cultural property. The terms of cultural property or cultural witness are explained. Cultural goods are considered expressions of human dignity. Accordingly, their use as a mere means contradicts the ethical responsibility of rational beings, whereas preservation and exchange of cultural goods become an ethical obligation. The traditional distinction between persons and things appears not appropriate for deciding the particular status of cultural goods, cultural property being an indispensable precondition of dignified human existence. It ought to be handed down to future generations. Restitution of cultural property is a further, though not absolute obligation. Ownership rights and the freedom to conduct trade and business do not automatically outweigh it. The buyer's claim to good faith will not necessarily protect him against the demand of restitution. With all this, the normative frame of the 1970 UNESCO Convention for preventing illicit trading in cultural property can be reconstructed: The ultimate goal of respectfully dealing with cultural property is the individual in his or her dignity as a human being, and his or her responsibility to society. Since the collective is a precondition of individual existence, it must be allowed to maintain and strengthen its identity. Cultural property is essential to that end. The respect of human dignity is thus the source of the obligation to respect cultural property.