Ferdinand Barnacle sums up very neatly here as he discusses the person who caused the market crash.
"He must have been an exceedingly clever fellow," said Ferdinand Barnacle.
Arthur ... was silent.
"A consummate rascal of course," said Ferdinand, "but remarkably clever! One cannot help admiring the fellow. Must have been such a master of humbug. Knew people so well—got over them so completely—did so much with them!"
In his easy way, he was really moved to genuine admiration.
"I hope," said Arthur, "that he and his dupes may be a warning to people not to have so much to do with them again."
"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."