The writing style

The book "An Inspector Calls" is designed as a theatre play. That's also the reason, why there are only eight characterized roles in the whole story. So also little theatre groups can perform this theatre play. The book is split in three acts, which are all continuous and played at the same place; the home of the Birling family. The whole story is written in the typical theatre form. It's only in the direct speech, sometimes interrupted from stage directions, like how the character sounds or some tips for theatre groups. For example at the moment as Arthur Birling was describing the Inspector to a police chief:

 "G-O-O-L-E ... a new man ... tall, clean-shaven. (Here he can describe the appearance of the actor playing the Inspector.) I see ... yes ... well, that settles it."

- Arthur Birling, p. 85, line 13-15 -

The author followed in the structure of the play the three Aristotelian unities. These were defined by Aristotle, an ancient Greek philosopher. According to him, a drama should follow these rules:

1. unity of action: a play should have one action with minimal subplots. (example: the whole story revolves around the suicide of Eva Smith.)

2. unity of time: the action in a play occur over a period of no more than 24 hours. (example: the main plot happens all at the same evening.

3. unity of place: the stage should not represent more than one place. (example: it all plays in the Birling's home) (Words: 247)

John.B, Priestly, the author of the play
(hdg.de)

Aristotles (Wikipedia)