In Othello, why does Shakespeare use light and dark imagery?

Othello is a play of contrasts. Shakespeare contrasts Desdemona's purity with the evil of Iago; the innocence of Desdemona with the cynicism of Emilia; Othello's honour with the falsity of Iago; Othello's self control at the start of the play with his complete breakdown at the end, and, at the very surface, Othello's black skin with almost the entirety of Venice. Crucially, Shakespeare does not use light and dark imagery solely in its physical sense, he also uses it to portray the internal qualities of his characters. Desdemona is often dressed in white to symbolise her purity and unblemished innocence. Shakespeare uses light imagery to present Desdemona as embodiment of all that is 'good'. Furthermore, her association with light is also used by Shakespeare to mirror the fact she holds an enlightened mindset for her time as demonstrated by her decision to betray her father and marry Othello. Whereas, Iago is frequently presented as going about his business in the dark of night and hiding in the shadows. In Act 1 Scene 1, Iago does not let Brabantio see his face when he comes to tell him Desdemona has married Othello. Iago consciously avoids shining the torch light to his face. Furthermore, Iago often watches his plans unfold whilst hidden. From the outset of the play, Shakespeare assigns Iago to the shadows: he is a character who conceals his true form and is innately 'bad'. Thus, Shakespeare's use of light and dark is firstly employed to mark out the innately good and evil characters.

Secondly, on a deeper level, Shakespeare uses the light and dark imagery to draw attention to the racism in Elizabethan England. Through utilising this imagery so extensively Shakespeare points out to the audience how virulent the racism was and relates the personal experiences of black people. Nearly all references to Othello by Iago are delivered through racist terms, he is referred to not by name but as "the Moor" and labelled an "old black ram" upon his first mentions. Meanwhile, nearly every character uses a racial slur to insult Othello at one point in the play. Typically, these slurs involve a mention of his black skin. Contrasting Desdemona's fair skin with Othello's, whilst also drawing attention to their intellectual compatibility, allows Shakespeare to subtly question the racist stereotypes. Indeed, the use of light and dark imagery emphasises the superficiality of the racism. Shakespeare shows how, internally, Desdemona and Othello share the same values but their difference in skin colour means society stamps a mark of complete incompatibility and incorrectness on their relationship.