The recycling of resource by the aggregate behavior of a diverse array of agents is much more than the sum of the individual actions.

With theory, we can separate fundamental characteristics from fascinating idiosyncrasies and incidental features. Theory supplies landmarks and guideposts, and we begin to know what to observe and where to act.

Looking back to data, we can see if the consequences are plausible; looking forward to theory, we can see if general principles are suggested.

The measure of performance of any given agent is the amount of money it accumulates through its actions.

If there is to be a competition, there must be some basis for resolving it. It is also clear that the competition should be experienced based.

Model building is the art of selecting those aspects of a process that are relevant to the question being asked. As with any art, this selection is guided by taste, elegance, and metaphor; it is a matter of induction, rather than deduction. High science depends on this art.

When a new building block is discovered, the result is usually a range of innovations.