Auteur theory is familiar to anyone who is a fan of the French cinema because the word originated as a description of a certain type of French film. Basically, it was a style that was directly connected to the director of the film, usually because he was both the involved in both writing the screenplay and directing the film. In the movies Week End by Jean-Luc Godard and The 400 Blows by Francois Truffaut, the director was involved in the writing also. Both directors were also proponents of the idea of auteur cinema, so their films would have had a flair that was similar to some elements of themselves. It can be said that the Truffaut film is the best representation of the style between the two because he was using scenes from his own life and that of his friends. Just as Tom Sawyer was a mix of the real life of Samuel Clemens (Mark Twain) and his contemporaries, Truffaut wanted to mix himself up in what would become one of the most loved of all French cinematic efforts. This directorial style can especially be seen in the scenes in which Antoine is talking to the psychiatrist. He tells his story in a fragmentary way, just the way someone would remember them. It seems that Truffaut may be, at least partially, telling his own story here. Or it is possible these are scraps that he heard from some of his friends about their experiences. Whatever the reason, these glimpses seem like memories. Godard captures hilarity more than anything else in his film. Godard liked to think of himself as an observer and analyst of real life. Susan Sontag quoted him as saying that "we novelists and filmmakers are condemned to an analysis of the world." The movie is based on a relatively ridiculous plot and some unlikely scenarios, but one long scene seems to embody the auteur movement. In one of the most famous traffic scenes in cinema history, Godard shows a relatively silent picture of a car (that of the protagonists) moving through a traffic jam. As with most traffic jams, people are upset and impatient until they reach the cause. An entire family...

This scene seems particularly real. It is the directors vision of the reality of a tragic incident. People cannot take time from their own miserable lives to acknowledge the tragic passing of a family. He is saying that people need to take stock of their environment and not be so engaged in their own lives. As a matter of fact, that seems to be the point of the entire film. The man and woman are running around frantically, they commit murder to gain a dead man's fortune, and then they find themselves the possible victims of cosmic justice. It is a reality that Godard paints due to his view of what the world is and what he believes needs to become of the ones who selfishly use others for personal gain.
The question also asks about both how realism was used in the two films and how the films were stylistic examples of the French new wave of cinema. Godard was a proponent of this school because he was first a critic of film and then a director, as was Truffaut. Bakin talked about the "historical, social and economic combination" of elements that made up realism (19). The idea is that a film should convey a reality in its production and direction that was missing from all but the Italian neorealist films. In The 400 Blows, Truffaut takes a stab at this style of realism during the movie, especially in the last shot. Godard continuously puts his characters in situations that may be ridiculous, but they are real. He seems to just be following a couple on a crazy outing. French new wave films were a sign of the times. All across the globe, people were embracing a new freedom which was probably, at least in part, brought on by the post-war era. People were a little more free spirited and wanted their art to demonstrate that freedom.

It seems that the only true continuity between the two films is that the directors show parts of themselves in the films. Of course, this can probably be seen in most movies. The scenes with the psychiatrist for Truffaut, and that in which the traffic jam is slowly traversed by the car for Godard seem to show a direct link…