One was a philosophical concept utilized within Doctor Sevrin's movement in the mid-23rd century. Spock was familiar with the idea. According to Sevrin, he and his group were One. Outsiders might also be One, and if they were they would understand his group's purpose. This purpose was to turn their backs on confusion and seek the beginning, Eden. Spock held great respect for Sevrin's movement, and one member, Adam, felt at one point that he was practically One. (TOS: "The Way to Eden" )