 In 1953, Calvin S. Hall developed a theory of dreams in which dreaming is considered to be a cognitive process.Hall argued that a dream was simply a thought or sequence of thoughts that occurred during sleep, and that dream images are visual representations of personal conceptions.For example, if one dreams of being attacked by friends, this may be a manifestation of fear of friendship; a more complicated example, which requires a cultural metaphor, is that a cat within a dream symbolizes a need to use one's intuition.