The situation of persons with Down syndrome has changed dramatically in the last years. On the one hand, their lifespan and quality of life have risen considerably; on the other hand, the chance of their very survival has fallen because of modern methods of prenatally diagnosing their disability. How did the modern defect-oriented view of things come to assume the place it has in medical affairs? The author seeks out the historical roots of this particular medical vantage point - the phenomenon of mongolism is well known since the 19th century - and also points out how far the race-biolological evaluation of Down syndrome has survived even to the present day and influenced not only the medical vantage point. The volume thus represents an important contribution to medical ethics and grants the other side, namely, the position of the persons involved, a special venue. German text.