Virology has provided our culture with many useful insights and the term 'viral' and the viral metaphor spring up in the form of computer viruses, viral marketing, memetics and memeplexes. Human beings are by nature metaphorical beings and understand complex concepts through metaphor and analogy. In other words, we understand something in terms of something else.

However, trying to understand a virus in terms of a virus throws the thinker into ever more greatly convoluted loops of logic. To think about HIV, what we need is a good metaphor for HIV - what is it 'like'? What organisms or systems do we know of that do the things HIV does? Could the emergent properties of billions of human beings transacting with each other be doing to our planet what HIV does to our bodies?