In summarizing the general condition of poverty, one observer concisely described it as “a form of exile, of being cut off from the larger society.”1 Efforts to define poverty more specifically perhaps risk incompleteness, since the causes underlying human destitution are so diverse and interrelated. This volume is an attempt to collate major dimensions of poverty and their impact on human development. In conjunction with the Council of Science Editors Global Theme Issue,2 we recruited established and emerging experts within nine topical areas, illness and disease, maternal health, health disparities, health care services, nutrition, education, housing, social and economic determinants, and engineering and technology. We asked them to provide their scientific perspectives on the causes and solutions relevant to human poverty. Twenty-five U.S. and foreign universities, as well as thirteen national or international organizations are represented. This collection focuses on the United States, as an example of a developed country in which poverty disrupts many lives,1 and provides an international context as well, through studies of developing countries in which the scale and impact of poverty are often more graphic and apparent. Thus, China, India, Nicaragua, Peru, Russia, and the countries of Africa are represented here, in addition to the United States. We hope the entire volume provides a better understanding of poverty, as it has for us, and that it may spur others to apply the rigor of science to understand, to reduce, and to ultimately eliminate poverty in our nation and around the world. The opening section is devoted to diseases of poverty, including chronic as well as acute infectious disorders. While not exhaustive in scope—measles, lower respiratory infections, and diarrheal illnesses are covered only by review of recent literature—the connections between neglected diseases and suboptimal development are abundantly evident. One worker remarked with regard to his disease of interest, “It's tied in with grinding poverty; where you find it maps almost perfectly with the poorest of the poor.”3 Many whose contributions are in Part I are active participants and leaders in efforts to directly reduce the human toll of these conditions. Their cautious hopefulness in the face of difficult odds indicates the progress their work is engendering. In Part II, maternal health is specifically addressed, and the critical need for support of mothers in avoiding the cycle of poverty is delineated. Indeed, this theme recurs throughout many other sections of this book. In Part III, health disparities in U.S. urban and Native American communities are formally addressed, whereas international health disparities are conveyed throughout most of the book. Access to health care and the problems of the uninsured are the subjects of Part IV. Basic human needs for food, education, and shelter are addressed in Parts V to VII, with papers from experts involved in the intimate connections between these topics and the experience of poverty. Part VIII considers social and economic determinants of human development, in both national and international contexts. Finally, Part IX discusses engineering and technological aspects of human development, which are especially critical for sustaining progress in poverty reduction in the developing world. While these nine sections provide a framework for the book, the boundaries between them are admittedly artificial. The answer to the question of why someone is poor will vary among individuals but invariably involves one or more of the issues addressed here. One author who supports preferential options for the poor has written, “Unless the poor are accorded some right to health care, water, food, and education, their lives will inevitably be short, desperate and unfree.”4 Poverty touches numerous aspects of human life simultaneously, and concerted efforts must be sustained in multiple arenas to secure meaningful gains. That is truly the message of this volume. We acknowledge the generous assistance of Dr. Evelyn Strauss, head of the initiative Scientists Without Borders at the New York Academy of Sciences (http://www.nyas.org/programs/borders.asp). Dr. Strauss referred us to numerous contributors for this book and proposed a section on engineering and technology. We also, and especially, thank Ms. Linda H. Mehta, acquisitions editor, Annals of the New York Academy of Sciences, for inviting us to participate in this project and for invaluable advice and guidance throughout each phase. Finally, we acknowledge the authors of these papers for their scholarship, compassion, and commitment. They are experts in science who also sense the humanity of the world's most vulnerable individuals and its casualties, while striving to reduce “the distance between the poor and the rest of us.”1 As editors, we thank them very much for contributing their knowledge, time, and energy to this project.