Four experiments supported the hypothesis that ordinary people understand free will as meaning unconstrained choice, not having a soul. People consistently rated free will as being high unless reduced by internal constraints (i.e., things that impaired people’s mental abilities to make choices) or external constraints (i.e., situations that hampered people’s abilities to choose and act as they desired). Scientific paradigms that have been argued to disprove free will were seen as reducing, but usually not eliminating free will, and the reductions were because of constrained conscious choice. We replicated findings that a minority of people think lacking a soul reduces free will. These reductions in perceived free will were fully explained by reductions in people’s perceived abilities to make conscious decisions. Thus, some people do think you need a soul to have free will—but it is because they think you need a soul to make conscious decisions.