Libet

Benjamin Libet (1916–2006) was an American neuroscientist and professor whose work on volition and the neural basis of voluntary action influenced discussions of free will. He spent much of his career at the University of California, San Francisco, where he conducted landmark experiments in the 1980s.

In these studies, participants performed simple, spontaneous movements such as finger flexions while EEG recorded brain activity. They were asked to report the moment they became conscious of the intention to move, using a rotating clock as a reference. Libet reported that an electrical brain signal known as the readiness potential began several hundred milliseconds before the participants' reported intention and well before movement commenced.

Libet argued that conscious intention did not initiate movement but that a veto mechanism—what he called free will in the form of conscious restraint—could still prevent an action. He proposed the concept of "free won't" to describe this veto capability, allowing conscious awareness to cancel planned movement after the readiness potential has begun.

Libet's findings generated extensive debate. Critics have questioned the interpretation of timing reports, the ecological validity of the tasks, and whether the readiness potential reflects decision-making rather than preparation. Later studies have offered alternative models, such as stochastic fluctuations in brain activity that may trigger movement, prompting the view that free will may operate as a veto rather than as the initiation of action. Nevertheless, Libet's work remains influential in discussions about the neuroscience of volition and responsibility.

Libet's research helped frame the dialogue between neuroscience and philosophy on free will, shaping subsequent experiments and theories about how voluntary actions are generated and controlled.