This book discusses 21 widely held progressive claims that Huemer argues amount to myths. Examples include psychology proving that people have implicit racist attitudes, women earning less than men for the same work, and science showing that global warming will destroy civilization without immediate drastic action. Huemer shows that the evidence for racism in implicit bias tests is highly questionable and also implies that respondents are biased towards women over men. The gender pay gap largely disappear when accounting for factors influencing earnings. Although there is a scientific consensus that global warming is real, scientists that worry about immediate catastrophes are outliers and resemble previous failed doomsday predictions. The discussion of each myth is very clear, with explicit references and arguments, and readers can follow the steps to make up their own mind. The latter part of the book discusses how to identify myths and why they often thrive. Huemer argues that unlike conservative myths – such as claims about the US 2020 elections were stolen and global warming denial - progressive myths often sound superficially plausible, are often not challenged, and often supported by tribal virtue signalling in progressive environments such as Universities. But truth matters and factually incorrect myths provide a poor basis for effective policies or efforts to address real challenges. Moreover, myths are pernicious, and can exacerbate polarization, undermine the strength of common ties and trust in the institutions that potentially can address social problems and challenges.