Why do dreams have symbols?

When you dream, the prefrontal cortex greatly reduces its activity, almost entirely shutting off. The prefrontal cortex is the part of your brain that processes language and performs thinking functions. So when you dream, your brain loses its ability to communicate using language and logic. Instead it communicates using symbols, metaphors and story, parts of our mind that are “earlier” or more primal in our evolutionary development.

This is the same reason why children will communicate using play. The psychologist Carl Jung says that the individual cycle of a person mimics the cosmic cycle of the human race. So, as we go from child to adult, we experience development similar to that of the human race from its earliest states to its current and future ones. In dreams, we go back to the “child” state of ourselves, so to speak.

Jung also thought that unconscious archetypes pervade across many cultures, myths, religions, and beliefs, down to the individual level, that manifest in every person without their being aware. These are the greater symbols that often appear in dreams–those which have the greatest emotional effect on us and are shared by the human race. Although they may take on specific meaning for each individual depending on their situation, even these are often traceable back to the larger, cosmic meaning.

Some Jungians even today debate whether these symbols are situated entirely within the human mind and are merely passed down genetically and through cultural memes, or whether they are actually outside of us and exist even beyond material existence.

A good example of this would be dragons–did so many cultures separated in time and space all just happen to make up the same symbol of the dragon, or were they basing it off of some out there, spiritual reality that does not appear in the realm visible to our everyday senses?

Another common example of archetypes would be something like the major arcana of the tarot cards, which communicate deep spiritual and philosophical knowledge shared by many cultures through pictures. Many archetypes can be found merely by comparing mythologies and religions from across the world and history and seeing what they share in common.