There was a time when people with Down syndrome were regularly encountered. But now, in 96% of cases detected by amniocentesis, the affected fetus undergoes an abortion. Voltaire knew that before being synonymous with stupidity, the word “idiocy” designates singularity. Returning to the evolution of the perception of "Mongolian idiocy" or to the Aktion T4 program set up by Hitler, the author wonders about the eugenic excesses of our society, about the medical incentive to abort rather than to undertake research for treatment. Contrary to dominant thought, Bruno Deniel-Laurent sheds new light on these "phenomenal" beings who are Down's syndrome. It also invites us to question ourselves about the society we want to build: the one that would give its place to singularities or the one that selects its members in defiance of any imperfection?