Blowing Hot and Cold: The Role of Estoppel

Abstract

This chapter provides a detailed account of a particular kind of estoppel. It argues that the law knows of a doctrine of “formal estoppel,” as contrasted with other, more familiar, variants. Formal estoppel is an extension of estoppel by deed, whereby a person who makes a formal statement as to their rights is estopped from subsequently denying that statement. It explains the nature and normative significance of formal estoppel in terms of the personal authority wielded by right-holders over the determination of their rights. Part of what it means to have a private right, as this chapter shows, is for the right-holder to have personal authority in relation to others’ understanding of their rights. The exercise of this authority extends to public statements made in respect of an individual’s rights. Statements by right-holders are an important way in which clarity can be reached in what an individual owes another. Recognition of the authority and responsibility of right-holders for public statements as to their rights implies that the law should treat them as binding and final. Formal estoppel is, then, the means by which courts recognize a question as to private rights as having been irrevocably decided by the right-holder.