Dr. Callahan co-founded the Hastings Center for bioethics, where he is shown here in 1979 or 1980. (Jacque Chenet/Hastings Center)

Daniel Callahan, a philosopher who helped found the modern field of bioethics, calling on physicians, patients and policymakers to confront vexing questions about the rising costs of health care and the sometimes competing goals of a long life and a good life, died July 16 at a hospital in Dobbs Ferry, N.Y. He was 88.

His death was announced by the Hastings Center in Garrison, N.Y., a nonprofit research organization that Dr. Callahan and a colleague, psychoanalyst Willard Gaylin, founded in 1969. The cause was chronic obstructive pulmonary disease, said Dr. Callahan’s son David.

For half a century, Dr. Callahan was one of the most respected thinkers in debates at the intersection of medicine, faith, law and politics. A Harvard-educated philosopher and the author of dozens of books, he entered the field of bioethics in the 1960s, when dizzying advances in medical science were prompting dilemmas previously undreamed of.

“The contraceptive pill was invented, the first heart transplants were performed, intensive care units . . . came into widespread use, complaints about the care of the dying grew as medical technology greatly expanded its capacity to keep very sick patients alive, and utopian dreams of genetic engineering were floating about,” Dr. Callahan wrote in a 2012 memoir, “In Search of the Good: A Life in Bioethics.”

“Medical progress was changing the definition of medicine, changing the conception of health, and changing the meaning of what it means to live a life,” he continued. “For someone educated as a philosopher, those were irresistible morsels.”

He spent most of the 1960s as editor of Commonweal magazine, a liberal Catholic journal, before ultimately adopting agnostic views and starting the Hastings Center with a $250 loan from his mother-in-law.

First operated from his basement, the center was initially known as the Institute of Society, Ethics and the Life Sciences and became a preeminent organization in its field. Dr. Callahan led the center as director and then president from 1969 to 1996 and later served as president emeritus.

He asked “deep, big, difficult questions . . . that required input from many different disciplines and a kind of courage to take them on,” Arthur L. Caplan, a bioethicist at the New York University School of Medicine, said in an interview. “He basically said look, our job is not to just fawn over medicine but to ask what is its purpose, what are its goals, what do we want it to do.”

At the center of Dr. Callahan’s worldview was what he considered society’s moral imperative to provide the greatest care for the greatest number of people.

Society spends “too much on health in comparison with other social needs, too much on the old in comparison with the young,” he observed, “too much on the acutely ill in comparison with the chronically ill, too much on curing in comparison with caring.”

He argued — often provocatively — against the provision of unlimited medical care to patients unlikely to live long or good lives, among them extremely premature babies and the very elderly. The financial cost was too high, he argued, and came at the expense of pressing needs such as education.

“We are only now beginning to see that we cannot have it all,” he wrote in his book “What Kind of Life: The Limits of Medical Progress” (1990), a volume that journalist Lee Dembart, writing in the New York Times, described as “a sober, bracing and important look at the realities of medicine and its costs.”

Reflecting on the care of very premature babies, he noted that, across the United States, hospitals with world-class neonatal ICUs are located a short distance from woefully underserved schools.

“Does it make sense,” he suggested, “to devote such a tremendous quantity of resources to saving smaller and smaller babies, and then thrust them into a society that is characterized by second- and third-rate schools?”

In his book “Setting Limits: Medical Goals in an Aging Society” (1987) — a finalist for the Pulitzer Prize for nonfiction — Dr. Callahan argued for an “age-based standard for the termination of life-extending treatment” for the elderly, despite what he conceded was the idea’s “widespread, almost universal rejection.”

“To him the question wasn’t so much a particular age,” Caplan explained. “It was, ‘Have you had the opportunity to enjoy our life [and] fulfill your projects?’ You don’t want to rob the young of their ability to do that.”

Dr. Callahan was widely credited with helping change the way physicians and patients view death and dying. He helped promote palliative care, in which patients with serious illnesses receive care designed to maximize the quality of their remaining life, rather than undergoing last-ditch interventions that may extend their life but only briefly, and in less comfort.

Caring, he emphasized, was often as or more meaningful than curing.

Daniel John Callahan was born in Washington on July 19, 1930. His father was a journalist, and his mother was a homemaker. When he was a boy, Dr. Callahan developed infected lymph nodes in the groin, leading to a series of painful procedures that he said made him “wary to this day of hospitals.”

He attended St. John’s Catholic college preparatory school in Washington, where he excelled on the swim team, before following the sport to Yale University. He received a bachelor’s degree in philosophy in 1952, then served in the Army counterintelligence corps before receiving a master’s degree from Georgetown University in 1957 and a PhD from Harvard University in 1965, also in philosophy.

During his undergraduate studies he met Sidney deShazo, whom he married in 1954. The Jesuit publication America described them as “a veritable Catholic power couple in the mid-1960s,” with an “intense, enduring and comprehensive partnership” that persisted even after Dr. Callahan distanced himself from his faith. He came to support abortion rights while his wife opposed them; together they wrote the book “Abortion: Understanding Differences” (1984).

In addition to his wife of 65 years, of Hastings-on-Hudson, N.Y., his survivors include six children, David Callahan of Santa Monica, Calif., John Callahan of Boston, Sarah Callahan of Cambridge, Mass., Mark Callahan and Peter Callahan, both of Hastings-on-Hudson, and Stephen Callahan of Plainfield, Vt.; and five grandchildren.

Dr. Callahan’s other books included “Abortion: Law, Choice, and Morality” (1970), “The Troubled Dream of Life: In Search of a Peaceful Death” (1993), and “Taming the Beloved Beast: How Medical Technology Costs Are Destroying Our Health Care System” (2009).

“Death is not necessarily an ultimate evil,” Dr. Callahan once said, and “efforts to conquer it offer no obvious social benefits.”