I won't loan him money as it is his vice and not because of his basic needs. If he won't learn his lessons, then, you are just tolerating his vice. Even if he is a family member, you need to be firm with your decision, else, he would encounter problem later on. Maybe, much worst.
Indeed. We won't loan him because we want make him to be aware of his mistake. He needs to realize that he is addicted to gambling and should be handed by doctors. If we loan him money, he never realizes it and he won't stop it. Sure, it must bring worse impacts in the future if he keeps gambling excessively. At a more severe level, addicts can commit criminal acts. So, we must ensure he stops gambling temporarily to recover the addiction problem.