Reviews of the literature on attention-deficit/hyperactivity disorder (ADHD) typically begin early in the twentieth century with the descriptions provided by paediatrician George Still. Physician Alexander Crichton, however, described all of the essential features of the Inattentive subtype of ADHD more than a century earlier than Still. This article presents a short biography of Crichton, looks at his 1798 publication describing attentional disorders in otherwise healthy individuals, contrasts his medical writing with the moralism of Still, and shows how his thoughts and observations are very much in accord with DSM-IV criteria for the Inattentive subtype of ADHD.