Brennan starts the book by grouping citizens into three categories: Hobbits (abstain from voting and are careless), hooligans (irrational and biased), and vulcans (perceptive and disinterested).

He contends that most citizens are vulnerable to misinformation, with which they hold biased points of view, and are also uninterested in obtaining useful knowledge about politics, which is attributable to rational ignorance.

The book presents Brennan's objection to the usefulness of ubiquitous political participation and deliberative democracy, the latter of which he argues is achievable only if all the deliberators behave like vulcans do, that is, to be respectful of differing views.

Also noted by reviewers is that Brennan's use of surveys to prove his claim, which suggests that ignorance is widespread among voters, does not consider scholars who have expressed skepticism about their reliability.

Brennan mentions three justifications for democracy: that it leads to more positive results than any other form of government does, it makes people more enlightened and educated, and intrinsically, it is beneficial, and he argues for the otherwise.

In the second chapter, Brennan states that citizens are likely to be manipulated by misinformation, such as conspiracy theories, for not having enough knowledge or being informed of evidence, and shows data proving how generally ignorant Americans are when asked about their national history and politicians' stance on certain issues.

In the eighth chapter, Brennan puts forward a number of epistocratic forms of government, which he notes have several institutions comparable to what democracy has but with a striking difference in the distribution of the right to vote.

[9] In an article for The Washington Post, law professor Ilya Somin praised him for "mak[ing] a strong case that the current electorate's right to rule is not nearly as defensible as we might want to assume".

She was also ambivalent in regard to Brennan's description of "most regular voters" nowadays that represent the hooligans and asserted that it was untrue even in the United States, from which the data cited in the book mostly come, writing of "a lot of evidence that humans are in-group/out-group thinkers and that group identity is used as a shortcut in preference articulation".

[12] In a 2017 column, Nathan J. Robinson of Current Affairs referred to the book as "the most spirited and comprehensive attempt at a philosophically coherent justification of despotic rule" among several that had been published since 2016, but faulted the author for not addressing the vulnerability of epistocracy being used for confirmation bias and its potential to help restore abolished hierarchies, such as the Jim Crow laws.

[13] Kevin J. Elliott of Contemporary Political Theory praised the "stimulating" book for its reliance on empirical publications while addressing such topics as voters' competence and behavior, but bemoaned that it does not consider criticism of these data.

For instance, the book shows surveys regarding citizens' poor performance in making competent decisions owing to their lack of knowledge but does not cite scholars questioning their reliability.