Consenting, Assenting and Promising

Abstract

Abstract This chapter compares and contrasts two normative powers, consenting and promising, each being a special case of ‘assenting’. The most fundamental difference is that consenting involves waiving a right, whereas promising involves incurring a duty. Both are future-oriented: just as you cannot promise to do something in the past, neither can you meaningfully give consent (i.e. permission) for something that has already been done. Both can be conditional, but neither can be merely hypothetical. Whereas consenting is self-executory, however, promising is not: something further needs to be done to execute a promise. Promises cannot be unilaterally revoked, whereas consent sometimes can be. The two also differ in the remedies for their breach. Both must be communicated, according to rule-governed, institutionally structured practices (typically but not exclusively certain forms of words). Both invite reliance.