Children tend to be missing from the literature on human rights. Sociology can help to fill the gap by providing evidence about the importance and benefits of recognising children's human rights, the dangers of not doing so, and joint rights-promoting work by adults and children. However, sociology has paid relatively little attention to human rights, and to the related topics of the Holocaust, human nature, real bodies, universal principles and moral imperatives. This paper examines splits in sociology around a central absence, which could partly explain these omissions. Then it considers how inter-disciplinary approaches and critical realism can help to theorise and validate "the inherent dignity and...the equal and inalienable rights of all members of the human family". The youngest children's rights illuminate meanings in all human rights, which depend less on the rational person approach than on recognising human nature, vulnerability and solidarity interacting with social structures.