There Will Always be Merdles

My dear Mr Clennam,' returned Ferdinand, laughing, 'have you really such a verdant hope? The next man who has as large a capacity and as genuine a taste for swindling, will succeed as well. Pardon me, but I think you really have no idea how the human bees will swarm to the beating of any old tin kettle; in that fact lies the complete manual of governing them. When they can be got to believe that the kettle is made of the precious metals, in that fact lies the whole power of men like our late lamented. No doubt there are here and there,' said Ferdinand politely, 'exceptional cases, where people have been taken in for what appeared to them to be much better reasons; and I need not go far to find such a case; but they don't invalidate the rule. Good day! I hope that when I have the pleasure of seeing you, next, this passing cloud will have given place to sunshine. Don't come a step beyond the door. I know the way out perfectly. Good day!'(Book II, Ch. 28).

Ferdinand Barnacle offers Clennam a truth about human nature.  He states that there will always be Merdles because there will always be people wanting more than what they have.  The adversely affected will mostly be avarious rich men, though there may be innocent victims, such as Clennam.  Merdle was likely the inspiration for Melmotte in Trollope's The Way We Live Now, though Trollope denied Dickens' influence.  Though the two characters are similar, based on their involvement in a Ponzi scheme, they are different personality types.  Merdle is reserved and reticent while Melmotte is loud and audacious.  Whereas Melmotte is a truly evil master manipulator, Merdle seems passive in his involvement in the scheme.  Trollope was more successful in creating a diabolical character on which to blame the fall of so many.  Nevertheless, Ferdinand's point remains.  Even recently, the scheme of Bernie Madoff proves that people will continue to gain the trust of others in order to cheat them.