By Elizabeth Scalia

Sentimentalism is an upbeat overemphasis on the inherent goodness of mankind that judges what is good or evil according to how well it accords with our feelings, or the feelings of people we want to impress.

By Eric Metaxas

Relativism is the assertion that truths, especially moral truths, have no validity independent of the “values” treasured by the person or society that asserts them.

By John Zmirak

Hedonism is the belief that the pursuit of pleasure— intellectual, emotional, or physical—and the avoidance of suffering ought to guide human decisions.

By Peter Kreeft

Progressivism, or “chronological snobbery,” confuses “new” with “true.” It also confuses facts with values, by using a factual, chronological term to carry a value meaning. Hence, something “modern,” “contemporary,” or “current” is “truer,” “better,” or “more reliable.”

By Robert Spencer

Multiculturalism is an anti-Western ideology that urges us to view the achievements of Judaeo- Christian civilization with a jaundiced eye and to overlook the flaws in other civilizations, in order to redress the results of past injustices. It is the intellectual equivalent of affirmative action quotas.

By Jimmy Akin

Anti-Catholicism, as used in this essay, is the belief on the part of other Christians that the Catholic Church has a false gospel, is a force for evil in this world, or (as some say) the “Whore of Babylon” leading people away from the true, “biblical” form of the Christian faith.

By Dwight Longenecker

Utilitarianism is the ethical theory that pleasure is the greatest good, suffering the greatest evil. Therefore, our actions must be guided by calculating what will bring the most pleasure or least suffering to the largest number, regardless of other considerations.

By Eric Brende

Consumerism is the contemporary face of avarice, which drives individuals to define themselves and judge their value in terms of material acquisition and the social status that it confers.

By George William Rutler

Cynicism is an intellectual stance that seeks to debunk the motives of other people and “expose” commonly treasured deals—generally for the sake of making the cynic feel superior to others, or freeing him from the necessity of attaining difficult virtues.

By Donna Steichen

Feminism is an ideological movement that sees women in families as akin to exploited workers in industrial factories: as a “domestic proletariat” that must engage in class struggle within the family rather than the workplace.

By John W. Keck

Scientism is simply an exaggerated belief in science. Scientism claims that the methods of the modern natural sciences provide our only access to the world and give the only kind of “truth.”

By Mark Shea

Americanism is the tendency, condemned by Pope Leo XIII, to put conformity with American culture and politics before the teachings of the universal Church.

By Jeffrey Tucker

Marxism is a philosophical system that asserts that the “real” explanation of most things that happen in society rests in the unequal relationships of money and/or power, which are inherently unjust and should be remedied by the use of force—either through a violent revolution that will impose equality, or through organizing society’s “have-nots” to take political power and seize what is “rightly” theirs by means of taxation and regulation.

By John Zuhlsdorf

[Modernists] lay the axe not to the branches and shoots, but to the very root, that is, to the faith and its deepest fires.... [T]hey proceed to disseminate poison through the whole tree, so that there is no part of Catholic truth from which they hold their hand, none that they do not strive to corrupt.