The Third Policeman 2

Never before had I believed or suspected that I had a soul but just then I knew I had. I knew also that my soul was friendly, was my senior in years and was solely concerned for my own welfare. For convenience I called him Joe.

Importance
This is the section of the book where the narrator's insanity is first apparent. Although he had been talking to a man he had killed, the narrator's conversation with Mathers can be written off as some kind of hallucination or dream. In this section, however, the narrator gives a part of himself a name different from his own. This soul character is not based on an actual character, like Mathers, but is instead completely invented. It is this complete departure from any kind of reality that alerts the reader that the narrator is no longer in his right mind.

Analysis
The first two sentences of this quote have multiple clauses and sections. The narrator also is treating the subject with a sense of seriousness in the first two sentences so the reader also feels a sense of seriousness. The last sentence, however, is abrupt and contains only one section. This change of syntactical style lends a humorous mood and shows the reader that this section will be absurd. The fact that the narrator named his soul, a part of him that is apparently authoritative, the simple name "Joe" also is humorous. The style reflected in this passage sets the tone for the rest of the chapter.