The ideas she represents would burn down the republic forever. Rioters, looters and arsonists can be countered by law and order, but the ideas behind the radical left cannot be stopped by riot shields, tear gas and bullet proof vests. The defense America needs today is not a matter for the National Guard or the Seventh Fleet. America requires voices on behalf of foundational ideas of freedom.

Freedom, it is often said, requires trust, and as trust goes, freedom goes. Societies with high levels of trust have wide enjoyment of freedom, whereas societies with low trust have low freedom, and high levels of surveillance and control. But trust, along with notions such as reason, truth and objectivity, is at low ebb today. They are all dismissed as "aspects of Whiteness."

The fact is that much of today's philosophy leads to skepticism, today's psychology to self-doubt, and today's political theory to suspicion. Suspicion is the only antidote to power and the potentially bad motives of others. Plumb the depths of modern critical theory, and you come away with one tip for your own safety: "Suspect thy neighbour as thyself." Little wonder 2020 has been a bonanza year for gun sales in America.

This deep-dyed suspicion, so corrosive of freedom, has been at the heart of the radical left ever since the convergence of the neo-Marxism of Antonio Gramsci and the Frankfurt School with the postmodernism of Michel Foucault and Jacques Derrida in the 1980s. God is dead, truth is dead, "essences" are gone, "binaries" are blurred, and all that counts is power. Such power without principle is a zero-sum game, or a scorched-earth style of war.

Social justice scholarship investigates our "discourse" and analyzes the pyramids of our "power relations," to identify who is the oppressor and who are the "victims." Social justice warriors then take over, "weaponizing" the victims, and using them to assault the status quo and its power and "privilege." Thus, gender is now pitted against gender, race against race, generation against generation and straight against gay and queer all in the name of a "reconstitution of society," aka the "second revolution" of the radicals' dream.

The peace of despotism?

The result of critical theory is a destructive criticism that leads to suspicion, antagonism, conflict, violence and the specter of scapegoating and assassination. America's covenantal "responsibility of all for all" degenerates into "the war of all against all," and Thomas Hobbes' well-known conclusion looms close Leviathan, "the mortal god of the state." Karl Marx assured us that the revolutionary state would wither away when the revolution triumphed. But not once in history has it ever done so. All that has withered away is the idea that the state will wither away.

Power without principle, especially political power, drives forward like a bulldozer unless checked by a stronger power. Thus, might conquers right, and the victory goes to the strong, while the weak go to the wall. But those who rely solely on power forget two things. First, power not only oppresses the weak, it corrupts the powerful. Second, unprincipled power can only lead to one kind of peace in the end the peace of despotism.

Reinhold Niebuhr always insisted that the bookends of history were authoritarianism, or order without freedom, and anarchy, or freedom without order. The American experiment has its roots in the Book of Exodus and what the 17th century called the "Hebrew republic." At its best, it is a vision of ordered freedom that balances the extremes with wisdom. Today, ordered freedom is being pulled apart, with some forces pulling toward anarchy and others to authoritarianism.

The loss of the vision animating the American Revolution would be a tragedy for America, the world and the future. A terrible lesson of history from Greece and Rome to Germany is that "the worst is the corruption of the best." Not only candidates, parties and policies are at stake this autumn. The underlying choice is between two revolutions 1776 or 1789 and its heirs. The outcome of this long and extraordinary year may prove to be as decisive for America as the Civil War.

Os Guinness, an Anglo-Irishman, lives with his wife, Jenny, in McLean, Va. He is the author of many books, including "Last Call for Liberty: How America's Genius for Freedom Has Become Its Gravest Threat."