What are the ethical limits of market behavior? If you can rightfully own something, when is it improper to sell it? If you may rightfully perform a task, may you also perform it for money? What does commerce add or subtract from the ethical status of an object or an action?

These are ancient questions, though undoubtedly the modern world has put them into stark relief. Commodification has become more and more widespread, and new items and services are being bought and sold all the time: The sale of kidneys, surrogacy, and even just standing in line have all had their critics. Our team of lead essayists this month, Jason Brennan and Peter Jaworski, argue that there do not exist any general limits to the scope of market behavior: If you may rightfully perform an action or own an item, you may rightfully buy or sell it. Not everyone agrees, of course. Joining us as well are the prominent social commentators Robert Kuttner and Benjamin R. Barber. Both argue that yes, there are meaningful limits to market behavior, and that societies ignore these limits at their peril.