Final answer:
The most widely read book on moral philosophy in America over the past decade is Principia Ethica by G. E. Moore. It explores topics such as the nature of goodness and moral obligation.
Step-by-step explanation:
The most widely read book on moral philosophy in America over the past decade is Principia Ethica by G. E. Moore. Published in 1903, this book presents Moore's influential ethical theory of non-naturalism and has been regarded as a foundational work in moral philosophy. It explores topics such as the nature of goodness and moral obligation.
Other notable works on moral philosophy in America include Utilitarianism by John Stuart Mill, Ethics of Duty by Kant, and The Works of Mencius by Mencius.