'confer an equitable right on B to compel fulfilment of the promise'?

Question

O'Sullivan & Hilliard's The Law of Contract (2018 8 ed). p 115.

5.79 First, there must be a clear and unambiguous promise or representation that the creditor will not insist on his strict legal rights, satisfying an equivalent test of certainty as is required for contractual obligations (see Baird Textiles v Marks & Spencer plc (2002) discussed at paras 3.15–3.18, and BMIC Limited v Chinnakannan Sivasankaran, Siva Limited (2014)). This requirement is not surprising—it is unacceptable to deprive a party of a legal right unless, judged objectively, this was the only plausible interpretation of his words or conduct. More important is the requirement that the promise must relate to existing legal rights, a significant limitation because it means there must be an existing legal relationship between the parties. Promissory estoppel cannot take the place of consideration when a contract is being formed for the first time between the parties, only (as in the Foakes v Beer problem) when existing contractual rights are being varied. Denning J did not emphasise this restriction in High Trees (although, of course, the landlord’s representation there was as to existing legal rights—the right to claim the full rent) but it has been applied ever since. Brennan J regarded this restriction as ‘illogical’ in Walton Stores v Maher (see para 5.94): ‘If a promise by A not to enforce an existing right against B [1.] is to confer an equitable right on B to compel fulfilment of the promise, why should [2.]B be denied the same protection in similar circumstances if the promise is intended to create in B a new legal right against A?’

Please ELI5 the bolded phrases.

1. Once 'an equitable right' is conferred 'on B', who's compelling the fulfilment? Who's the promisee ?

2. Why would "B be denied the same protection in similar circumstances if the promise is intended to create in B a new legal right against A"?

Answer 1

Your question #1:

Equitable rights are the rights an entity has by virtue of an overarching sense of "The Just Thing" as distinct from rights explicitly granted by an agreement.

If A promises B that A will not enforce some right that A has under an existing agreement between them, B receives a right to compel A to honor or fulfill that promise; but unless there had been a quid pro quo for that promise, B's right to compel A to fulfill the promise is not obtained contractually but by equity.

Your question #2.

Brennan is saying that in a new agreement with B, A ought to be able to promise not to enforce a right that A already has, i.e. a pre-existing right unrelated to any agreement between them, and that B should receive an equitable right to compel A to fulfill that promise. By restricting estoppel to existing contracts, B is being denied the opportunity to enter into a new agreement with A in which A would promise not to enforce some right A has, whereby B in turn would obtain an equitable right to compel A to fulfill the promise. Brennan asks : why should B be denied that opportunity to rely upon equity? The restriction which limits estoppel to existing agreements forces B to offer A some consideration in return for A's promise if B wants that promise as part of a new agreement. As a result, B's right to compel A to honor its promise would not be founded in equity but in contract law.

Disclaimer: I'm not a lawyer, but I've been swindled by a few of them.

P.S. Consider the verb sound which has a legal definition (see #19) here: http://dictionary.reference.com/browse/sound

Answer 2

What Brennan J objects to is the doctrine that

Promissory estoppel cannot take the place of consideration when a contract is being formed for the first time between the parties, only [...] when existing contractual rights are being varied.

Brennan J regards this as illogical.

• Primary estoppel arises when A promises not to enforce an existing right—A's right under an existing contract. In this case B acts subsequently in reliance on that promise; consequently, B has the right to compel A to fulfil that promise.

• But if that is the case, why should B not have the same right ('Why should B be denied the same protection') when A makes a similar promise with respect to a new contract? A promise is a promise, whenever it is made; why does B lose that equitable right when a new contract is being written?