Normative Externalism argues that adherence to one’s own personal moral or epistemic principles is not the ultimate standard of correctness. Instead, what matters are the correct principles—doing what is right and believing rationally according to objective standards. This stance has far-reaching implications in both ethics and epistemology, challenging several established views. In ethics, it undermines the idea that moral uncertainty should be treated similarly to factual uncertainty, disputes the notion that moral ignorance often excuses wrongdoing, and refutes the perception of hypocrisy as a vice. In epistemology, the book proposes new treatments for higher-order evidence, peer disagreement, circular reasoning, and suggests innovative approaches to address these issues. By juxtaposing debates in ethics and epistemology, the author highlights common themes, such as the diminished appeal of following one’s own principles when they are terrible or lead to risky actions. Additionally, it explores the regress problem inherent in requiring individuals to follow their principles, suggesting that adhering to correct principles is the optimal solution.

The book, authored by Brian Weatherson and published by Oxford University Press, delves into these complex arguments over 260 pages, offering a compelling argument for why external standards of correctness are more important than internal ones in both moral and epistemic contexts. Its publication date is May 19, 2019, with ISBN-13: 978-0199696536.