While diligent readers who behave according to the plan should recognize the coherence of this project, it has, I admit, an inescapably far-flung character. The long chapter titles attest to my earnest effort to lay bare the reason behind such ostensible madness. If they fall short, I may yet hope that that readers will be amused by the abundance of curiously-pertinent episodes narrated here.The sixth chapter, for example, features a mostly-forgotten Norwegian asylum doctor, Ludvig Dahl, who received a state research grant to investigate certain parishes with disproportionately high rates of mental illness. For decades, beginning with its first census of insanity in 1828, Norway had shown a distinctively high insanity rate, especially for a country of farmers and fishermen. Many, including Dahl himself, suspected that this result was merely an artifact of its uniquely thorough census. He proceeded, nevertheless, to survey in exacting detail some of the most insanity-ridden parishes of Norway. He concluded in his book-length report that a high concentration of insanity might have less to do with environmental or cultural differences than with the presence and transmission of a specific hereditary tendency or factor (in written Norwegian, Anlæg).It requires, perhaps, a mad-statistical specialist to love the tables constructed by these alienists (asylum doctors). Tabular reasoning, in any case, was their most basic tool for investigating patterns of heredity. Dahl’s contemporary Wilhelm Tigges was perhaps the most diligent and ambitious of the German table-makers. He set out to arrange his abundant data to poke holes in the rising French theory of hereditary degeneration. The reasoning here is a bit complicated, and the data work must have been extraordinarily burdensome. In a strict sense, he failed, for dégénérescence grew into a great cultural phenomenon, taken up with gusto by an international movement of physicians, writers, and artists. I hope that some readers at least will laugh, as I do, when confronting this weirdly incongruous—yet somehow effective—effort to seize and debunk the mystic fluidity of degenerative heredity.Apart from its introduction and conclusion, the book begins in 1789 with an episode of royal madness and a desperate search for data to determine the likelihood of George III’s recovery and it culminates with some brooding over the geopolitical consequences of a mass campaign to sterilize every bearer of a supposed recessive gene for mental defect. Not long after I began the project, it dawned on me that madness makes an appearance in many, possibly most, movies, novels, and operas. And not for nothing.The madman (or woman) in a performance is usually there for comic effect, but the actual experience of madness is dismayingly tragic. Many of my characters, especially in the early 1800s, envisioned that the insane could be cured and the disease practically eliminated. The association of insanity with a science of heredity implied a loss of faith in cures and, simultaneously, a dream that the regulation of human reproduction might provide a solution of a different sort. Modern historians have debated whether the true origins of human genetics were bound up with eugenic tools and ambitions. My “unknown history,” of “genetics in the madhouse” aspires to show that eugenic ambitions were present, so to speak, in the very DNA of human genetics. Here I use ironically a locution that I generally prefer to avoid.I regard the subject matter of this book as a formative phase in a long history of genetic overreach. The faith that mental disabilities could be relieved most effectivity by restricting reproduction, already prominent in the nineteenth century, was greatly strengthened after 1900, when the late recognition of Gregor Mendel’s long-ignored work inspired extraordinary anticipations of eugenic triumph over mental defect. I do not claim any competence to anticipate what might be possible in the future, but we should at least be realistic about the past and present. The Human Genome Initiative, for example, presented a vision of critical discoveries arising from laboratory research supported by massive computer power. The data work of madhouse doctors, though tending also to overreach, at least acknowledged their dependence on data and insights from mundane human institutions such as hospitals, schools, prisons, and state surveys.Human genetics did not spring from the flowing curves of DNA like Athena from the head of Zeus, but had its start amidst the stench, the moans, and the punishing remedies of medical-bureaucratic institutions for the treatment and confinement of the mad. Genetics continues to rely on data and tissues taken from such people. It has proved far from straightforward to do much to relieve their suffering.