A man’s a man for a’ that

A man’s a man for a’ that
 

Likewise I saw it this morning I´m uncapable of understanding it. Any help ?

It is Robert Burns, and it's not usually worth trying to understand it. In this case, however, it's saying that a man is a man regardless of social or wealth status. Egalitarianism. :)

a' is short for all here. "For all that" :approx: "a pesar de todo eso".