Paul Root Wolpe examines the ethical implications of new science -- genetic modification, neuroscience and other breakthroughs that stretch our current philosophy to the breaking point. He's the chief bioethicist at NASA, among other appointments.

Stephen Coleman studies applied ethics, particularly the ethics of military and police force, and their application to human rights.

Danielle Allen is an expert on the intersection of ethics and democracy.

Kelly Richmond Pope researches organizational misconduct, ethics and fraud.

Over the past 35 years Peter Saul has been intimately involved in the dying process for over 4,000 patients. He is passionate about improving the ways we die.

Jonathan Marks works at the intersections of ethics, law and policy -- writing and speaking about torture, obesity, fracking, health care and other pressing issues of our time.

Based in Bulgaria, Steve Keil creates companies around big social and environmental goals.

Sometimes controversial, always practical ethicist Peter Singer stirs public debate about morality, from animal welfare to global poverty.

Kwame Anthony Appiah is a philosopher, cultural theorist and novelist. His latest book is "The Honor Code," exploring moral revolutions.

Think of Surya Mattu as a data detective. As he writes: "I am interested in figuring out the ways in which algorithmic systems harm people."

Anthropologist and media scholar Mary L. Gray focuses on how the everyday use of technology (including artificial intelligence) transforms our lives -- for better and worse.

Philosopher Thomas Pogge wants to ensure medications get to those who need it most. He has published on a wide range of subjects such as global justice and human rights.

Michael Patrick Lynch examines truth, democracy, public discourse and the ethics of technology in the age of big data.

Rodrigo Canales wants to understand how individuals influence organizations or systems--even those as complex as the Mexican drug cartels.

Britt Wray's work is about life and what we make of it: past, present and future.

Jennifer Doudna was part of inventing a potentially world-changing genetic technology: the gene editing technology CRISPR-Cas9.

Alice Dreger studies history and anatomy, and acts as a patient advocate.

Kate Darling investigates the relationship between humans and robots -- now, and in the future.

Dr. Nir Eyal is an international authority in population-level bioethics with research in health inequalities, health promotion and research ethics, especially in resource-poor settings.

Juan Enriquez thinks and writes about the profound changes that genomics and brain research will bring about in business, technology, politics and society.

Ronald Sullivan is a leading theorist in the areas of criminal law, criminal procedure, trial practice and techniques, legal ethics and race theory.

Britain's former prime minister Gordon Brown played a key role in shaping the G20 nations' response to the world's financial crisis, and was a powerful advocate for a coordinated global response to problems such as climate change, poverty and social justice.

William Black is a professor of economics and law at University of Missouri, Kansas City.

Kriti Sharma creates AI technology to help address some of the toughest social challenges of our time -- from domestic violence to sexual health and inequality.

Iyad Rahwan's work lies at the intersection of the computer and social sciences, with a focus on collective intelligence, large-scale cooperation and the social aspects of artificial intelligence.

Veerle Provoost studies genetic and social parenthood in the context of donor conception.

Ian Goldin is director of the Oxford Martin School. Through the school's program of research, collaboration and education, he's powering new, cross-disciplinary thinking about global problems from the near and far future.

Dr. Gregory Stock's levelheaded look at the hotpoints where tech and ethics connect (or short circuit) have made him a popular guest on TV and radio. He directs the Program on Science, Technology, and Society at UCLA.

Travis Rieder wants to help find a solution to America’s opioid crisis -- and if that sounds a bit too lofty, he’d settle for making clear, incremental progress in a responsible, evidence-based way.

Krista Tippett hosts the national public radio program "On Being," which takes up the great, animating questions of human life: What does it mean to be human? And how do we want to live?