In real life, people’s physical differences rarely have much symbolic meaning; if you have a birthmark or a short leg, this just means you have a birthmark or a short leg. Historically, however, physical aberrations have been associated with moral shortcomings. The more beautiful a person was, the closer they were thought to be to God, and vice versa. Although humanity has shifted our understanding about this topic in recent years, in literature physical attributes do still tend to carry symbolic meaning.
Having a physical mark or disability is seen in a very different way today than it has been within different periods in history, and it can sometimes be difficult to reconcile our contemporary perspective with the views of people in the past on this subject. Indeed, there is a whole subset of literary scholars who work on disability studies and grapple with these questions.
When characters have scars, it gives a sense of their history, and therefore scars can be a way for authors to reveal information about their characters’ pasts. Sometimes this is more information than the character knows about themselves, as in Oedipus Rex. Oedipus’ lack of knowledge and curiosity about his scars turns out to be his fatal flaw, which will ultimately lead to another physical disability (blindness). When groups of characters all have scars, this can convey a message about how people have suffered within a large-scale event or era, such as the First World War or slavery.
There is a reason why we speak of mental and emotional scars as well as physical ones. In many ways, scars are a real-life symbol, a physical phenomenon with built-in symbolic connotations. Even innocuous scars have a story behind them, and thus scars are an extremely effective method through which authors tell the stories of their characters’ pasts.
Mary Shelley’s monster in Frankenstein (1818) is constructed in a lab out of bits of machinery, highlighting fears about the shifting cultural emphasis from religion to science, and of societal changes brought about by the industrial revolution. However, although the monster Frankenstein creates is grotesque, the real monster is Dr. Frankenstein himself, as it is he who plays God and disrupts the laws of nature. Similarly, in Oscar Wilde’s The Picture of Dorian Gray (1890) Dorian looks innocent and beautiful on the outside but is actually corrupt and evil, a modern, ironic subversion of the conventional association between beauty and goodness.
The examples Foster provides are both from the 19th century, but fears about the way technology is changing human existence and the power of humans to manipulate their image has arguably only intensified since then. Indeed, one of the most powerful aspects of literature is its ability to make thematic connections through intertextuality that highlight how similar our own society is to those that came before us.