Boswell's The Life of Samuel Johnson, published in 1791, is still considered to be the finest biography in the English language and is the single best source for our knowledge of Samuel Johnson in his interactions with his friends and acquaintances.
In an entry in his journal in 1780, Boswell noted:
"I told Erskine I was to write Dr. Johnson's life in scenes. He approved."
Boswell's early intention to capture Johnson's life "in scenes" is particularly important because, much later, Boswell also observed that the best biography of Johnson would reflect not only what he wrote but what he "said, and thought: by which mankind are enabled as it were to see him live. . . ."
Boswell's narrative technique, for the most part, centers on the alternation of quoting lengthy passages from Johnson's voluminous writings and the inclusion of Boswell's own authorial interpretations of Johnson's life. For example, rather than relying on Johnson's own recollections of his life, Boswell adds his own observations of Johnson's behavior:
He had no settled plan of life, nor looked forward at all, but merely lived from day to day. Yet he read a great deal in a desultory manner, without any scheme of study, as chance threw books in his way. . . .
If we are looking for merely objective observations of Johnson, we must be disappointed, but if we seek an interpretation of Johnson, then Boswell has met that goal admirably. Consistent with Boswell's style, he does not evaluate Johnson's behavior in this observation; he merely adds an observation that could only be made by someone with an intimate understanding of Johnson's private history. The observation that Johnson lived from "day to day" and that he read in a "desultory manner" is characteristic of an omniscient or limited omniscient narrator.
Boswell's style throughout the biography is to establish a setting in which he can show Johnson in the best light and then to depict the scene in such detail, using dialogue to add verisimilitude, that the reader feels like an ease dropper at a private conversation. One of the results of this technique is that Boswell becomes the authoritative keeper of Johnson's actions and words across a wide range of Johnson's later life when he had become, according to the novelist Tobias Smollett, the "Great Cham of Literature." Our understanding of Johnson, therefore, is a carefully crafted memory recorded and created by Boswell himself.
In a sense, Boswell's style in the biography mirrors Johnson's own--when he is interpreting or commenting on Johnson's behavior, Boswell's prose can be relatively ponderous, solemn--slow--but when he recounts scenes in which Johnson acts or speaks, the style is lively, replicating the cadence of conversation and creating a picture of Johnson's interaction with friends and acquantainces. More important, however, Boswell's technique of recording Johnson's words creates a new kind of biography in which a man's actual words become his legacy, perhaps the greatest service Boswell could have performed as Johnson's biographer.