My favorite example of emergence thus far has been ideas about consciousness. I was just reading a section of "Gödel, Escher, Bach" in which the author includes a quote, by Roger Sperry on the subject, which I find very palatable: "... if one keeps climbing upward in the chain of command within the brain, one finds at the very top those over-all organizational forces and dynamic properties of the large patterns of cerebral excitation that are correlated with mental states... near the apex of this command system in the brain we find ideas... the causal potency of an idea becomes just as real as that of a molecule, a cell, or a nerve impulse. Ideas cause ideas and help evolve new ideas. They interact with each other and with other mental forces in the same brain, in neighboring brains..." The author also mentions the idea about explaining such an emergent phenomena as a result of a "strange loop", where the so-called emergent level influences the simpler/sub/lower levels whose interactions are in turn responsible for the emergent level to begin with. Going along with the same example, he points out then that consciousness would emerge "at the moment it has the power to reflect itself." This type of back and forth or reciprocation reminded me of stigmergy in the context of termites-- where termites change their environment by laying down pheromones somewhere and in turn their behavior is influenced by the new, changed environment, then adding more pheromones where ever this is some already and ultimately building a nest. Anyway, I'm looking forward to learning about emergence in other contexts as well. As someone who likes to understand relationships across disciplines/systems/whatever the idea of accounting for things through emergent properties is very exciting/encouraging and 'comforting', if that makes any sense.