The phrase "who says contractual, says justice" or "qui dit contractuel dit juste" does not fully express the truth of our present reality, where the phrase itself falls into doubt, since a contract does not always result in fair obligations because it is often an expression of unequal wills. When the French judiciary realized that the absence of justice in a contract might arise as a result of the contractual freedom afforded to the contracting parties, they developed the idea of Commutative Justice based on ideas such as Piller's decision, for which Commutative Justice is one of its most important applications. However, the causation theory in the Palestinian Civil Code Draft and the Indonesian Civil Code was limited to monitoring the existence of the corresponding obligation, whatever it was. In this context, this paper seeks to prove that the provisions of the causation theory in the Palestinian Civil Code Draft and the Indonesian Civil Code can be used as a means to monitor the economic contractual equilibrium of a contract. To do so, the legal provisions of the causation theory should be analysed using a comparative analytical approach with the French judicial decisions to illustrate the Palestinian and Indonesian legislative deficiencies and the need to adopt the French judicial approach.