The themes of forbidden love, tragedy, loss and isolation are closely interlinked in “Romeo and Juliet”. Shakespeare uses imagery throughout the play to highlight their importance. The forbidden love of Romeo and Juliet is described using religious language, imagery of contrasting light and darkness, and nature; tragedy is emphasised by the imagery of death throughout the play; isolation can be seen in the language and actions of both the central characters, and loss is experienced in terms of both lost love, and loss of life, adding to the weight of the tragedy.
The theme of forbidden love is introduced in the Prologue, with celestial imagery which suggests that the lovers are doomed from the start by saying "star-crossed lovers"(Prologue.5). Later, just before he meets Juliet, Romeo has a strange premonition that his "mind misgives”.
Some consequence yet hanging in the stars…
By some vile forfeit of untimely death”
Constant references to the stars throughout the play point to their fates already being sealed and doomed. When they first meet, Shakespeare uses a sonnet which is heavily laden with religious imagery using words like:"profane"; "holy shrine";"pilgrims";"devotion"; "palmers"; "faith". This suggests they have God on their side, which adds a sense of purity and intensity to their love. The way in which the lines of the sonnet are divided between both Romeo and Juliet, adds a sense of balance and equality. Their love for each other is mutual, which deeply contrasts with the one-sided love Romeo experienced with Rosaline. Later, in Act 2, religious imagery again symbolises the purity of their love in "a bright angel...heaven.....baptised....dear saint" and continues this theme from Act one, indicating the strength of their love. It also enables us to take Romeo more seriously in his intentions towards Juliet, because otherwise, he could appear fickle, due to how quickly he has fallen out of love with Rosaline. Even Friar Lawrence claims
Holy Saint Francis, what a change is here!...
So soon forsaken?
In the other hand, the Friar does point out, that Rosaline saying the following quotation, "... knew well/ Thy love did read by rote, that could not spell" (II.iii.87), suggesting this 'love' was simply quoted from books, rather than expressing what was truly in his heart.
Additionally, Shakespeare makes many references to light and darkness in scenes which focus on Romeo and Juliet. When Romeo first sees Juliet, he uses imagery of light to describe her,
".... she doth teach the torches to burn bright"
"as a rich jewel in an Ethiop's ear
a snowy dove trooping with crows”
Which indicate the transformation love brings to Romeo's life. This contrasts with the dark imagery which follows them throughout the play. Symbolic of the secret nature of their forbidden love and which foreshadows the ending, where, just as when he first meets her, "Her beauty makes this fault a feasting presence full of light" (5.v.85), symbolising the purity of their love and which gives their love a spiritual quality. Being with Juliet literally brings light into Romeo's life, where his previous love for Rosaline only brought misery, symbolised by darkness. Before we are even introduced to Romeo, in Act 1.i, Lady Montague uses imagery of "clouds" and "shady curtains" to describe Romeo's mood to Benvolio and claims he,
"Away from light steals home ...
And makes himself an artificial night”
Which symbolise the deep depression in which he finds himself, and which is miraculously lifted by Juliet's presence. Rosaline represents the theme of loss of love and we see Romeo's emotional torment. Shakespeare uses oxymoron to highlight Romeo's tormented state of mind,
"O brawling love, O loving hate...
Feather of lead bright smoke, cold fire, sick health"