The Theories

The theories associated with Hitchcocks is:

and

The aspects of filmmaking that, in addition to the two theories mentioned above, meant the most to him was:

and

These theories and aspects of filmmaking, that had so much significance in the Universe of Hitchcock, will be described below.

Suspense is without any doubt his most important filmtheoretical contribution to cinematic art.
The method of suspense implies that the audience knows at least what (and preferably more than) the main character knows. This is why we normally know who the guilty in a Hitchcock movie is. This knowledge enables the thoughts and feelings of the audience to be activated, which implies that we not only is watching what is going on, suspense makes us enter into the spirit of the plot.
Hitchcock used to describe the difference between suspense and surprise like this:

Four men is sitting at a table playing poker. The scene is rather boring. Suddenly, after 15 minutes, we hear a big bang - it turnes out there was a bomb under the table. This is called surprise as it isn't what we expected would happen.
If we watch the same scene again with the important difference that we have seen the bomb being placed under the table and the timer set to 11 AM, and we can see a watch in the background, the same scene becomes very intense and almost unbearable - we are sitting there hoping the timer will fail, the game is interrupted or the hero leaves the table in time, before the blast. This is called suspense.

The difference is that we in the scene using surprise gets approximately 15 minutes of boredom and a few seconds of excitement (at the moment the bomb goes off), in the scene using suspense we've got 15 minutes of intense excitement.
The use of surprise is the trade mark of the traditionel detective film of the "whodunit" ("who did it?") genre, a type of movie were the entire plot is focused on the murder investigation itself. This was a genre Hitch disliked because the entire movie is spoiled if the identity of the guilty one is revealed too soon - e.g., if a Tv station is telling who is the guilty one on their competitors detective series, just before the final episode goes on air.

Suspensefull scenes can also be created using "active camera": an exciting scene is not filmed in a boring total, the camera - and ultimately the audience - is going up close and participating in the scene.
Hitchcock's movies was suspensefull which was a logical choise, since the genre he focused on and refined was the thriller.

MacGuffin is a concept that is difficult to define. It is something that seems to have great significance to the people involved, but to Hitch it has absolutely no significance at all. It is something that has no significance to the movie itself, but it is able to initiate a conversation or movie plot. And above all, a MacGuffin has the advantage that the director doesn't have to explain it in detail, since it don't have any significance in the context of the overall picture.
The concept is said to originate from a story his friend and scriptwriter Angus MacPhail once told him:

Two men meet on a train to Scotland.
One of them puts a packet in the luggage rack. "What is that?" his fellow traveller asks. - "Oh, that is just a MacGuffin" is the answer. - "A MacGuffin? What is that?". "Well, you see, that is something you use to catch lions in Scotland". - The fellow traveller is pleased with that answer, but then it dawned on him: "There is no lions in Scotland". - "Isn't there? Then this can't be a MacGuffin".

Normally he would use a harmless and rather insane MacGuffin, but in 1944 (when he finished the script to "Notorious") he got in trouble with the FBI. In this movie the MacGuffin was some uranium contaminated sand on wine bottles in the villains cellar - and this was, as you probably know, the year before they dropped the nuclear bomb on Hiroshima.

While working with the scriptwriting everything was mapped out with mathematical precision, even where the actors should look, camera angles and how the scenes should be used in the cutting room.
He didn't write the scripts himself, he had a panel of writers working for him. These writers met him and Alma (who had "final cut") every day, which gave him the opportunity to tell them exactly what he wanted.
When he made a script it was already to begin with divided into "shots" containing a description of camera angles, composition, lighting, setting and duration - he made a detailed description of the visual sequence. When this was done he had the writers write down the dialogue. The reason why he worked like that was that he wanted to tell a story using only purely cinematic means - when the sound film was introduced it became possible to make "pictures of people talking" (i.e., it was possible to make a movie containing nothing but dialogue without having to master any cinematic skills).
The script was so detailed that the movie was almost cut before it was shot.
Hitchcock found it difficult to work with authors who had already made a name for themselves, since he didn't really need an independent writer but a skillfull secretary that knew how to write down his thoughts, in a way that filled in the holes in the movie's "architecture" in a reliable way.
In addition he had a tendency to differ from the literary source when the movie was based on a novel. He only used the central plot, when the book was read he forgot about it and made a movie of his own, containing other characters and scenes and a completely different story - he didn't make what you would normally call a screen version of a novel.

In the script everything was mapped out in a degree that gave him total control of the movie's creation. The only aspect of the movie he didn't control during the scriptwriting, was the music. But he had a way of exercising complete control of the music too. One of the composers from the British era, Louis Levy, have told that even though Hitch knew nothing about notes, arranging and orchestrating, you would still leave the meetings with a melody inside your head - he knew exactly what he wanted and how to formulate his requirements in a clear way, that left the composer without any doubt about how to write the music.

Hitch's idea of an ideal film was a movie were the dialogue didn't support the visual sequence, the dialogue should contradict the visual sequence. E.g., if a woman is crying she don't have to say she is sad - that is obvious, the line would be needless (the line could contradict the visual sequence by saying something like this: "Oh, don't make me laugh!"). But to his regret he had to recognize it would demand too much time having the writers write the lines, if the dialogue should contradict the sequence through the entire movie.

Production Code and their claim for a happy ending forced Hitch to adapt and turn the rules into his own advantage. This resulted in his speciality: the ambivalent ending, i.e. an ending that seems happy if you look at it in a superficial way, but if you give it a more thorough consideration you know it isn't what it seems to be. He also used this ambivalence for characters, i.e. a character that isn't what he/she seems to be - this can be used to make the hero look weak and unsympathetic, or make the villain look sympathetic. This ambivalence was - in combination with the use of suspense and in particular active camera - used to make identifications. He could among other things make us identify with the villain - as he said: "The better the villain, the better the picture!".

In addition he preferred to use cinematic virtuosity in his work. He would often film the scenes in an unconventionel way showing virtuosity, which gave evidence to eminent skills.

In Hitchcock's opinion the Alpha and Omega of filmmaking was the montage (cutting), he thought it was at this stage the movie's dramatic progress was created.
The performance of the actors depends on how the director is using the material in the cutting room. This was probably the reason why he was dissatisfied with the fact that the actors sold the tickets and earned the biggest fee, even though they didn't have any influence on the final movie (or their own part) - it is the director who is responsible for creating the movie.

Normally Hitchcock didn't like theories, but one filmtheoretical experiment pleased him very much. This was the famous experiment by the Russian director Lev Kulesjov, an experiment that reveal how important the montage is:

He shot a close-up of the actor Ivan Mosjoukine, who had a neutral facial expression.
This picture was used in different contexts: in connection with a dead child the face reflected grief, in connection with a bowl of soup the face reflected hunger, in connection with a sleeping woman the face reflected love.

This experiment showed us that if the actor have just the right neutral facial expression, it is interpretted in the context it is used in.
This was why he didn't want the actors to play out overwhelming emotions on behalf of the audience - he wanted us to think and feel, not just to watch. Theatrical overacting that didn't suit the screen meant nothing to him. He preferred understatement, i.e. when the actors are underacting and perhaps even playing against their part - this was probably why James Stewart was one of his favourite actors, as he was a true master of understatement. Hitchcock described the difference between overacting and understatement using the following example: if you push an american actress into a pool with cold water, she will begin to overact her part in a hysterical way; a british actress will behave with dignity, as if this is something she is exposed to every day.

Hitch had his problems with actors that didn't conform to his total control. He would even terrorize them to get it his way. E.g., when Joan Fontaine was playing the leading role in "Rebecca" (1940), Hitch told her that no one on the crew (except Hitchcock) liked what she was doing - which made her play her part the right way, a little scared of everyone.