semiotics

                  Fernand Khnopff: I lock my Door upon Myself  (1891, München, Bayerische Staatsgemäldesammlungen)
                                                                            Available at:
                                    http://moniquespassions.com/art-nouveau/fernand-khnopff-i-lock-my-door/
                                                                    (Accessed 20 April 2012)

There is always a secret behind a sign. If we want to find out the secret is better to go after. Fernand Knoppff`s Door is definitely one of the signs which makes the viewer curious. Even if the door is open in front of the viewer, we still remain curious . A door can be a symbol for different things. It can be closed or can open different worlds, different spaces. It also can separate spaces from each other. We can tell a door has a double function. Just like God Janus in ancient Rome was responsible to stay at the front gate of the city but also he was responsible for the past and the future. ( http://www.worldwidewords.org/weirdwords/ww-jan1.htm, 1996-2012).

Available at:

                                     http://www.balassikiado.hu/BB/netre/Net_szimbolum/szimbolumszotar.htm#Janus
                                                                   Accessed at 20 April 2012

The Door which is leading from the human world to the divine world, can represent the knowledge one might know or which remains a secret. The door also can represent the woman`s secret. If it is open it can mean the losing of virginity (http://www.balassikiado.hu/BB/netre/Net_szimbolum/szimbolumszotar.htm).

The secret behind the door can be the secret of "Fallen Woman" represented by John Henry Fuseli by his picture called "The Nightmare."

                                                                            Available at:

                                                 http://irishgothichorrorjournal.homestead.com/maria.html
                                                                      Accessed 20 April 2012

The Fallen Woman in Victorian art and literature generally denotes the prostitute or the woman who has fallen prey to her sexual appetites. Her fall is frequently connected with horses. The critic Nina Auerbach refers to ‘the symbolic use of horses in novels about fallen women from three different countries’(44) referencing Leo Tolstoy’s Anna Karenina, Émile Zola’s Nana and George Moore’sEsther Waters."(http://irishgothichorrorjournal.homestead.com/maria.html).
I think "The fallen woman" can be the same with one who locked the door upon herself. She is the one who knows the secret, maybe has to stay behind the closed door as the society would never accept her but she is a wise woman.

Reference list:

http://www.worldwidewords.org/weirdwords/ww-jan1.htm (1996-2012) Accessed 20 April 2012.

Fernand Khnopff: I lock my Door upon Myself  (1891, München, Bayerische Staatsgemäldesammlungen)
  Available at http://moniquespassions.com/art-nouveau/fernand-khnopff-i-lock-my-door/ (Accessed 20 April 2012)

 http://www.balassikiado.hu/BB/netre/Net_szimbolum/szimbolumszotar.htm#Janus Accessed at 20 April 2012

 http://irishgothichorrorjournal.homestead.com/maria.html Accessed 20 April 2012