Agents and Goals in Evolution

In evolutionary biology, there is a mode of thinking which is quite common, and philosophically significant. This is ‘agential thinking’. In its paradigm case, agential thinking involves treating an evolved organism as if it were an agent pursuing a goal, such as survival and reproduction, and treating its phenotypic traits, including its behaviours, as strategies for achieving this goal. Less commonly, the entities that are treated as agent-like are genes or groups, rather than individual organisms. Agential thinking is related to the familiar Darwinian point that organisms’ evolved traits are often adaptive, but it goes beyond this. For it involves deliberately transposing a set of concepts—goals, interests, strategies—whose original application is to rational human agents, to the biological world at large. There are two possible attitudes towards agential thinking in biology. The first sees it as mere anthropomorphism, an instance of the psychological bias which leads humans to see intention and purpose in places where they do not exist. The second sees agential thinking as a natural and justifiable way of describing or reasoning about Darwinian evolution and its products. The truth turns out to lie in between these extremes, for agential thinking is not a monolithic whole. Some forms of agential thinking are problematic, but others admit of a solid justification, and when used carefully, can be a source of insight.