The linguistic term prolepsis refers to a construction where a structural complement of the matrix verb is semantically related to the predicate of an embedded clause. In an example like I believe of John that he likes Mary, the proleptic constituent John is related to the position occupied by the coreferential pronoun he.. At first sight one may take the proleptic constituent to be an argument of the matrix verb with the pronoun establishing an anaphoric dependency, but things are more complex. First, the construction is possible with a very wide range of matrix verbs, casting doubt on the argumenthood of the object. Second, a coreferential element is obligatory, which argues against a mere aboutness relationship. There is conflicting evidence concerning the base position of the proleptic object. On the one hand, there is solid evidence from anaphor binding and superiority that the proleptic object occupies an A-position in the matrix clause. On the other hand, the proleptic object reconstructs into the complement clause. This suggests that the proleptic object originates in the embedded clause, but an analysis involving movement from the complement clause fails for conceptual (Improper Movement, Freezing) and empirical (selective reconstruction effects) reasons. It is proposed that these paradoxical properties follow if the proleptic object is licensed by predication. The complement clause involves a base-generated operator which turns it into an open sentence. The coreferential pronoun is the variable bound by the operator. The proleptic object, then, is the subject of the predication. The relationship between the proleptic object and the silent operator involves ellipsis, as does the relationship between the operator and the coreferential pronoun. Ellipsis derives the (selective) reconstruction effects, and predication explains the necessity of a coreferential element.