From the discoveries of the principles of genetic inheritance in the 19th century to the development of the concepts of human molecular genetic disease in the 20th century, the treatment of human disease has been transformed from a focus on symptoms to the goal of correcting underlying genetic defects which are the cause of many human diseases. Here, Theodore Friedmann shows that this scientific revolution in medicine compares in importance to Copernicus's demonstration of the sun-centered order of the planetary system, the 18th and 19th century discoveries of the cellular structure of living systems, germ theory of disease, the invention of anaesthesia, and the discovery that genetic information is stored and transmitted by DNA.

The Origin and Development of Genetic Therapies explores the origins and early developmental history of the medical field of gene therapy. Friedmann examines the early failures and increasingly promising clinical "successes" for this new approach to cure genetic disease and explores how the concepts of gene therapy can affect human hereditary and human evolution.