Calvin contends that brains think by virtue ofbeing "Darwin Machines", machines that emulatebiological evolution but on a much reduced timescale. He goes on to suggest how these processesmight occur in biological neural networks.Unfortunately his ideas have not been developedto the point of actual algorithms and experiments.This is what is missing. While recurrent excitationis known to occur what about Calvin's "triangulararrays", "lateral cloning", "hot spots", "synchronousrecuitment", "attractor formation", "patterncompetition", "memory recall", etc. etc.? All ofthese ideas need to be fleshed out, coded inartificial neural network software, and sought incomputer simulations. Such experiments are what isneeded to turn speculation into theory. As a happybiproduct if such experiments prove successful onewould have a working prototype artificial intelligence.