How do you define success? Different people define it different ways of course.
But most of the time, people in conversation qualify the term success. They say things like "He is very successful in business" or "She has a successful marriage".
So what does success mean in the generic sense? What does it mean when someone says John is successful?
Here's my definition:
A successful person is one who is able to achieve a level of material and emotional comfort in which their needs and desires are easily met. A successful person is someone who is happy in both their personal life and is able to acquire most material goods without consideration.
The more successful the person, the more the happier they are in their personal life and the more material desires they are able to fill without consideration.
Example:
A person who is happy with their home life, loves their job, can afford to go to the movies at any time they want, doesn't worry about how much dinner costs or how much a hard cover book they like costs is more successful than the guy who hates his job, has to go to the matinee showing of the movie, and has to wait for the discount paperback book to come out.
So in a debate, when I say someone is more successful than someone else, I am saying that that person has achieved some combination of being happier with their home life, happier in their career, and more financially capable of obtaining what material goods and services they desire without concern.