The following are the essential elements of an obligation, except
a. An active subject, who has the power to demand prestation, also known as the obligee or creditor.
b. A passive subject, who is bound to perform the prestation, also known as the obligor or debtor.
c. Object or prestation, which is the promise or particular conduct to be performed in the performance of an obligation, and may consist of giving, doing or not doing a thing.
d. Efficient cause, the tie which binds the parties to the obligation, also known as juridical tie or vinculum.
e. The form in which the obligation is manifested.