What a man is depends on his character; but what he does, and what
we think of what he does, depends on his circumstances. The characteristics that
ruin a man in one class made him eminent in another

I think the quote should be "who a man is..." and i also think that i would judge a person based on their character and not their circumstances. Also The characteristics that a man has does not make or break him. i think no matter your class you are supposed to find a position in society to work towards. This could be how you want your future lineage to live whether it be upper class , middle, or if you really wanted to, lower- it depends on the type of culture you like. you should have goal for a new experience and you should utilize and exploit your personal talents (characteristics of you) to get there.

I agrue that the single most useful characteristic that applies in every single class is the salesmen attitude. On a low class level you see a lot of illegal sales and everyday hustling. On the middle class level from an early age you are taught the buy/sell/trade market of poekmon and yugioh and crazy bones and all other collectibles, and the upper class level you generally just playing monopoly with your money but still all about sales.