As with any historical study, including that of knowledge and ideas, the progress of the semiology of the theater is subject to periodicity. The aim of any division into periods is to obtain a global view, even at the price of simplifications, but it can also bring out the hidden aspects of the phenomena under study.
The semiology or semiotics of the theater, that is, the application of the idea of sign to the art of the spectacle, has a long past, in which several stages may be distinguished, and first of all those that I would call the presemiology and the protosemiology of the theater.