Victorian scholars point out the meaning of "gentleman" was very
contested during the 19thC, which is why so many people, including
Charles Dickens, wrote about them. Here I quote from the
"Victorian Web" site: "The concept of the gentleman was not
merely a social or class designation. There was also a moral
component inherent in the concept which made it a difficult and an
ambiguous thing for the Victorians themselves to attempt to define,
though there were innumerable attempts, many of them predicated
upon the revival in the nineteenth century of a chivalric moral
code derived from the feudal past. Sir Walter Scott defined this
concept of the gentleman repeatedly in his enormously influential
Waverley Novels, and the code of the gentleman — and abuses of it —
appear repeatedly in Victorian fiction. "The essence of a
gentleman," John Ruskin wrote, "is what the word says, that he
comes from a pure “gens,” or is perfectly bred. After that,
gentleness and sympathy, or kind disposition and fine imagination."
Dickens was an “author of relatively humble origins who desired
passionately to be recognized as a gentleman, and insisted, in
consequence, upon the essential dignity of his occupation.
Great Expectations, which contains a great deal of
disguised self-analysis, is at once a portrait or a definition of
Dickens's concept of the Gentleman and a justification of his own
claim to that title.