The viewpoint character, Mr. Utterson, is introduced to us as a lawyer, who is frequently “the last reputable acquaintance and the last good influence in the lives of down-going men.” He remains constant throughout the story. He is clearly the character with whom the author hoped the reader would identify. He is austere in his own appetites and simultaneously possesses enough sense of privacy to allow others to go to the devil in their own ways. Yet he has enough charity (or what passes for it) to look after their affairs when they are ruined.
The reader can intuit from the character of Mr. Utterson, and from the fact that there is not a speaking role for anyone of lower social status than a lawyer’s assistant or a butler, nor for any woman in the entire story, that the author may have led a circumspect life. Stevenson may have written no dialogue for people unlike himself because he may not have conversed with them enough to be able to write dialogue for such characters. For a world traveler, he was strangely inexperienced with people. He knew his limitations as an author, and generally did not exceed them.
“Know thyself” is one theme of this story, and it becomes clear that some who think they know themselves have much to learn, either about their own hidden qualities or about the merits of standing by someone when you have stood aside while he ruined his life.
This story is an illustration of what Carl Gustav Jung later theorized as the separation of the persona and the shadow. Dr. Jekyll has put so much of himself into his public persona, that he wishes to spare none of his energies for his shadow.
Man is such a changeable animal-a chameleon in his own right. Those who hide from this truth are destroyed by it, or disabled by the effort to live without change.