This paper introduces a scheme for object-oriented programming within the framework of the procedural interpretation of Horn clauses. Metalogical operations, such as assert and retract, or extensions to logical operations, such as unification with read-only variables, are not required. The effects of object-oriented programming are obtained through a control strategy that interprets some negative literals as procedure calls and others as instances of objects. A new type of logical formula, the object clause, is introduced to describe procedures that modify instances of objects. The paper concludes with a discussion of aspects of object oriented programming, such as class hierarchies, and how they can be realized in the new framework.