Mithen’s hypothesis is that, until this period in prehistory, our ancestors were knowledgeable but their knowledge was confined within domains. One domain was of understandings of interactions in the social group, another was the properties of plant foods, and so on. At a certain point in the evolution of the human brain, the domains of our cognitive structures started to interpenetrate. Metaphor was born: marks on the wall of a cave could become a rhinoceros.
The mental process of metaphor later allowed the ancient Greek lyric poet Sappho to write: “Love shakes me again, that bitter-sweet creature.” Love is itself, and also something else. A piece of social understanding with a physiological aspect is interpenetrated by the experience of food, in a phrase that was so striking that the idea of love being bitter-sweet has lasted 2600 years. Such crossings of domain boundaries can have an arresting quality, so that we recognize them as special, as larger than ourselves.
Among the many important implications of this idea are that metaphor is not just ornament, not even just a linguistic phenomenon, it is fundamental to the way we think. It supports our abilities to make models of our world, in language, film, and other media. It also enables some permanence for externalized mental products. Though thought is ephemeral, art lasts and can spread to others. So although one can imagine a lover whispering an improvised poem into her lover’s ear, usually a poem lasts beyond the moment of its conception, and can travel. Also, art is not just frippery. As Maja Djikic has pointed out, the effort required for people 31,000 years ago to journey deep into caves, to make torches that enabled them to see, to manufacture pigments, indicated that they felt what they were doing was important.
The most recent issue of the magazine, Greater Good, is entitled "Why make art?" (To see and read this issue, click here.) I have an article in this issue which, as well as including a discussion of Mithen's work, has a summary of the recent results of our research group (Maja Djikic, Raymond Mar, Keith Oatley). My article is also in our archive or magazine articles, to access which you may click here.
Steven Mithen (1996). The prehistory of the mind: The cognitive origins of art and science. London: Thames and Hudson.
Steven Mithen (2001). The evolution of imagination: An archeological perspective. SubStance (# 94/95), 28-54.
Keith Oatley (2009). Changing our minds. Greater Good, 5, (3) Winter.