The title comes from one of the mythical tales enriching the book; the complete sentence is: “Light is the left hand of darkness, darkness is the right hand of light.” Light and darkness are obviously two contrasting elements which are seen here as interrelated; the juxtaposition of seemingly different images or ideas is clearly one of the themes of the novel and, especially, of the myths. We are reminded of Blake’s Marriage of Heaven and Hell, where opposites are put together to surprise and puzzle the reader; for example, one concept (good) cannot exist without its opposite (evil), as “the Lamb” needs “the Tyger”. In LeGuin’s book, one contrasting element defines the other, and one cannot survive without the other. Every creature is endowed with contradictory components which, instead of crippling the person, make him/her whole; the duplicity of all creation is underlined every step of the way. This clearly refers to the inherent twofold nature of the Gethenians but also to the relationship between Genly Ai and Estraven. The two find a profound understanding in the story before and after Estraven’s death, which is a powerful - if sad - reminder that we can come together as one even if we belong to distant worlds and that wars waged against what is different are not necessary.