[8] In 1984, he and wife Sidney Callahan—who took an anti-abortion position—co-edited a book, Abortion: Understanding Differences, that included essays from people on all sides of this issue.

The center, originally named the Institute for Society, Ethics and the Life Sciences, and based in Hastings-on-Hudson, New York, was the world's first research organization devoted to bioethics.

It played a pioneering role in developing this field by bringing together scholars from across different disciplines, including medicine, law, science and philosophy.

Such noted leaders in bioethics, such as Arthur Caplan and Robert M. Veatch, began their careers at the Hastings Center.

[10] During that time, he wrote numerous articles and edited multiple books, including on issues of death and dying and genetics.

Upon its publication, The New York Times Book Review wrote: "This is a pivotal work that poses hard questions and proposes provocative answers.

"[11] The book attracted wide attention and generated significant controversy, including two volumes of essays debating or criticizing Callahan's ideas.

[12] In 2009, Callahan was interviewed by NPR about his reflections on Setting Limits as he aged and responded to charges of hypocrisy for benefitting from expensive medical interventions.

In addition to his books on abortion and health care, he is the author of The Tyranny of Survival (1973); Ethics in Hard Times (1982); The Roots of Bioethics: Health, Progress, Technology, Death (Oxford University Press, 2012); and The Five Horsemen of The Modern World: Climate, Food, Water, Chronic Illness, and Obesity (Columbia University Press, 2016).