My interest in Jane Eyre revived when I realized that it could be incorporated into the system of symbols which Iqbal had used to interpret the world literature in order to decipher the ambitions which societies nurture in their hearts often without knowing it themselves. Hence I do not claim that the interpretation which I am offering was also known to Charlotte Bronte when she published her book in 1847 (although I have a few interesting observations on that matter as well).
I see Jane Eyre as the spirit of Christianity (which makes her the same as "the spirit of all human beings" described by Syed Ahmad Khan quite independently in his short story 'Time Bygone' in 1873). In that case, Rochester becomes the embodiment of Western civilization and the body politics of Europe. Its dark secret is the fruits of colonialism which it is trying to hide in the attic because that is a bargain that went wrong: the marriage with the mad woman took place in Jamaica (a colony), and it has only brought anguish.
However, Jane is a moral phantom like destiny itself, who cannot be diverted. Her principles do not bend any more than a force of Nature. Hence she leaves Rochester (the spirit of Christianity leaves the body politics of Europe). She does not find solace in the company of puritans either (just as Christianity is no more content with monasticism and is yearning to become a guiding force for civilization again).
The mad woman does not represent the colonized nations. She represents no individual. She is an epitome of that moral weakness in Rochester himself which led him to seek fortune abroad. It is that same moral weakness, now personified in the shape of this woman, which brings doom to his estate: she puts fire in which she burns herself as well as the estate of Rochester, and he loses his eyesight temporarily.
Uncanny, that this is exactly how Iqbal prophecied the end of colonialism in his seminal poem 'March 1907': "Your civilization will commit suicide with its own dagger." I do not mean to suggest that Iqbal was deliberating over the matrimonial problems of a 19th Century governess when he wrote this climactic poem about destinies of nations, yet it is extremely interesting to note that a particular interpretation of Jane Eyre brings out an embedded message completely identical to that of Iqbal.
Is it my personal interpretation? Well, I belong to a tradition where every writer since Nezami Ganjavi in the 12th Century (and including Rumi, Jami, Bhittai, Sir Syed and Iqbal) has used the metaphor of the beloved to mean the spirit of a society, identical to "the spirit of all human beings." It is only natural for me to interpret Jane Eyre in this manner.