quantum meruit

http://en.wikipedia.org/wiki/Quantum_meruit
有非常好的解釋

[節錄]
A Man (plaintiff in this hypothetical) talks to a neighbor (defendant) and tells him he's going to build a wall on their property that will give a benefit to both the man and his neighbor. The neighbor neither agrees nor disagrees with what the man wants to build. The man builds the wall, and then asks the neighbor to compensate him for the benefit of the wall that he conferred on the neighbor (usually half the value of the wall). The neighbor refuses. The man is entitled to some compensation based on quantum meruit. This is because there was an implied promise between the man and the neighbor, which is derived from contract law, because the man was acting under the assumption that the neighbor would pay for part of his services(see Estoppal). The plaintiff files suit in court on the basis of quantum meruit. The plaintiff makes an estimation of value conferred on the defendant, which the defendant has not paid. Plaintiff will likely win because of quantum meruit. The winning of the case will be directed as an assumpsit on a quantum meruit.

我覺得那個例子其實有點問題:

要成立一個simple contract,主要條件要有intention, agreement and consideration

agreement需要有一個offer,一個acceptance.可是例子中"the neighbor neither agrees nor disagrees with what the man wants to build." 證明了neighbor是silence,而silence通常不會被當作一個acceptance除非under circumstances: