A meaningful theory of human biology cannot be reduced to chemistry and physics, but instead must be understood in its own vocabulary of evolution, competition, reward, desire, reputation, avarice, friendship, trust, hunger, and so on—in the same way that traffic flow will be understood not in the vocabulary of screws and spark plugs, but instead in terms of speed limits, rush hours, road rage, and people wanting to get home to their families as soon as possible when their workday is over.
