Does a bacterium pursue goals? Does a plant make decisions? The idea of biological agency, that living things devise ends of their own and behave accordingly, has a long and uncomfortable history in biology, and it is now making a comeback.
At first glance the concept seems unscientific. Attributing purpose to cells looks like a return to vitalism, the discredited notion that life contains a special force absent from ordinary matter. Defenders respond that agency need not be mysterious. A bacterium swimming toward nutrients is regulating its own state relative to an environment, and that capacity for self-directed regulation may be precisely what distinguishes living systems from machines.
The debate matters because it shapes how researchers frame their questions. Treat a cell as a mechanism and you look for causes; treat it as an agent and you ask what it is trying to achieve. Both framings have produced real results, and the argument is really about which one earns its place in a mature science of life.
