1. Why is the existence of a sanction or punishment necessary in case of non-observance of the law?
2. What is the distinctive feature of a civil obligation?
3. Why are natural obligations not enforceable in court? Does it mean that they are useless or irrelevant?
4. Why is it required that obligations imposed by law must be expressly determined by legal provisions or clearly deduced therefrom?
5. The parties to a contract are given the right to stipulate or agree upon anything. Is this absolute or not?
6. Why is the debtor obliged to exercise ordinary diligence pending the delivery of a specific thing?
7. When does the creditor acquire personal right?
8. When does the creditor acquire real right?
9. As a general rule, what is needed to place the debtor in delay or default? What are the exceptions to the general rule?
10. What is the distinction between incidental fraud/dolo incidente from causal fraud/dolo causante?
11. In general, what is the effect of impossible condition in an obligation? What are the exceptions?
12. What is the effect of period in an obligation?