M. H. Abrams says that a symbol is anything that signifies something else. Abrams also notes the distinction between public and private symbols. The public symbol, such as the cross, is (apparently) understood by everyone in a given culture. The private symbol, such as an obscure poetic allusion, isn’t.
This distinction, however, is open to debate. Not everyone in a given culture interprets the cross in the same way.
In literature a symbol is
a word or phrase that signifies an object or event which in turn signifies something, or suggests a range of reference, beyond itself.¹
In Jungian depth psychology, the symbol is an image that mediates forces from the collective unconscious to ego consciousness. These forces can be healing (the cross image) or destructive (the serpent image).²
Jung believes that symbols arise from the unknowable archetypes but are understood through archetypal images. Archetypes apparently mingle among themselves; likewise, archetypal images are discrete but exhibit similarities. For Jung, psychic energy flows between the collective unconscious and the symbol in a two-way process.
Jungian Erich Neumann says the symbol acts as both as an “energy transformer” and as a “moulder of consciousness.” As an energy transformer the symbol facilitates the ego’s experience of the numinous, arising from the collective unconscious. As a moulder of consciousness, the symbol operates on the level of collective consciousness by contributing to a given culture’s ideology.
Jung believes that the conscious and unconscious parts of the mind are linked, so trying to ignore one in favor of the other is not a good idea. He’s widely quoted from The Undiscovered Self (1958):
You can take away a man’s gods, but only to give him others in return.
Along these lines, charismatic political leaders of the mass state cannot avoid being glorified or demonized. This happens through brute force, clever calculation and public fascination and projection. Jung believes, for example, that a placard of Joseph Stalin expresses an archetypal force articulated on the conscious level that both sways and oppresses individuals.
A more contemporary example would be the psychological effect that massive banking towers (symbolizing Big Business) have on the poor and disenfranchised. And in ancient cultures such as Greece, Rome and Egypt, impressive architecture probably had a similar effect on slaves, the exploited, the underprivileged and on less affluent visitors from foreign lands.
No discussion of the symbol would be complete without mentioning semiotics and poststructuralism. These contemporary paths of inquiry might not go into great detail about depth psychology, but they’re important for deconstructing cultural assumptions (see also sign, signifier, signified, denotation, connotation, Foucault, Derrida, Barthes, Bourdieu).
¹ A Glossary of Literary Terms, 2005, p. 320.