Legal Principle: The object of an agreement is lawful unless it is forbidden by law; is of such a nature that, if permitted, it would defeat the provisions of any law; is fraudulent; involves or implies injury to the person or property of another person; the court regards it as immoral; it is opposed to public policy.
Factual Situation: A promised to pay Rs. 150 per month to his wife so long she remained away from him and did not object to his living in adultery.
Issue: Is the agreement valid?