 We have explored sufficient conditions for treating another merely as a means. But just as challenging as pinpointing them is specifying when someone uses another, but not merely as a means. According to one proposal, if an agent uses another, she does not use him merely as a means if he gives his voluntary, informed consent to her use of him. To fix ideas let us say that the consent of the person being used is voluntary only if he is not being coerced into giving it and informed only if he understands how he is being used and to what purpose(s). This proposal seems intuitively attractive. If a person agrees to someone using him and understands her ends in doing so, then how can she be treating him merely as a means?