Abstract
Field theory offers a new account of how teleology and goal directed systems work. Under field theory, goal-directedness arises from fields that are external to, and envelope, the entities they direct (McShea 2012, 2016; Babcock and McShea 2021). A teleological entity immersed in a field behaves persistently and plastically, following a trajectory directed by the field. When the head of a heliotropic sunflower follows the sun from east to west throughout the day, it is immersed in a field composed of the sun’s rays. Without the sun’s rays, the head would cease to move since there would be no direction. Or consider an autonomous car that is guided to a waypoint by GPS satellite signals. The satellite infrastructure forms a field, and it is the field that guides the car to its destination regardless of where the car starts its trip or what obstacles it may encounter. One virtue of the theory is that it collapses the distinction between natural and artifactual goal-directed systems. In an earlier paper, we established that fields are external and physically describable. Here we explain more precisely what fields are, in a way that operationalizes them so they can be deployed in the sciences and elsewhere. First, we detail some of the features we take to be the hallmarks of fields. And we argue that fields are multiply realizable, not reducible to a single physical description. For example, there are no special physical properties to be found in the sun’s rays that are common to all fields. At the same time, solar radiation is a purely physical phenomenon. What makes the sun’s rays a field is their place in the goal-directed system that consists of the combination of the sunflowers and the sun. Second, field theory helps make sense of the controversial role that mechanisms play in biology in general, and in goal-directed systems in particular. Outside a goal directed system, a field and a mechanism might be interchangeable. However, within the context of a goal-directed system, fields and mechanisms are quite different. Fields guide, while mechanisms respond to guidance, and non-teleological objects do neither. Third, we develop a kind of test for the existence of fields, based on a hypothetical elimination process. For any entity showing teleological behavior, we consider if such behavior could be accounted for without positing the existence of a field. This is to say, we consider whether there could be any teleology absent the existence of spatially larger, physical structures which direct a contained object. We argue that while it is possible to imagine such systems, the teleological systems we find in the world always seem to employ fields. From an engineering perspective, fields seem to be all but essential for teleology.
