Mr. Pickwick is one of Dickens' greatest creations. A fat old man who becomes a romantic adventurer, Mr. Pickwick acquires form and character as the novel progresses. He has misadventures because he is living in a spiritual Eden, unaware of the presence of deception; then he undergoes a moral education. By the end of the novel he has become the incarnation of Christian charity and goodwill. His growth is entirely convincing, one of Dickens' very few instances of success in showing a believable, virtuous character.
A large part of Dickens' achievement in creating Mr. Pickwick lies in the three-dimensionality of the portrait. Dickens does not develop his characters the way a modern novelist does, by showing their internal conflicts. Dickens depicts his characters from the outside, through their speech, appearance, and gestures. Nevertheless, he gives us a full portrait of Mr. Pickwick's character, and the spiritual development can be inferred from the actions. Mr. Pickwick is loyal and protective toward his friends, gallant toward women, hot-tempered toward the nasty or unscrupulous, affectionate and self-sacrificing toward his servant, forgiving and merciful toward persons who have wronged him. He is also boyish, innocent, fun-loving, a bit absurd as he goes from one scrape to another.
The adventures have a definite pattern to them, which reveals Mr. Pickwick's character. One plot involves trying to frustrate Jingle's matrimonial schemes; another deals with fighting Mrs. Bardell's breach-of-promise suit; a third involves aiding true love. Each of these plot lines has to do with romance, with combating mercenary plans and furthering disinterested love. Even though Dickens cannot draw serious love successfully, we believe in Mr. Pickwick's efforts to assist it.
Finally, Dickens reveals Mr. Pickwick's character through his relationship to Sam Weller. Sam begins simply as Mr. Pickwick's valet. Then he becomes emotionally involved in his master's attempts to thwart Jingle and Mrs. Bardell, which establishes him as an ally. Then in prison both men prove their willingness to make personal sacrifices for the other, and Sam becomes like a son to Mr. Pickwick. It is partly in the growing depth of their relationship that we come to accept Mr. Pickwick as a real person.