48 The defendant also puts her claim for recovery of the sum of $6000 on a quantum meruit basis. Quantum meruit is essentially a common law principle, rather than one that arises in equity , although it is difficult to divorce equitable considerations entirely from the equation. In Monks v Poynice Pty Ltd (1987) 8 NSWLR 622, Young J identified, at 663 - 664, four situations in which quantum meruit can arise. First, where there is a request, express or implied for the performance of the service. Secondly, where the party benefited, accepted or acquiesced in the provision of the service under circumstances where it must have known that the service was not being rendered gratuitously. Thirdly, where the service is necessary for the protection of property. Finally, where the service conferred incontrovertible benefit on the defendant and it would be unconscionable for the defendant to keep the benefit of the service without paying a reasonable sum for it.