The 20th century philosopher-novelist Ayn Rand, author of “The Fountainhead” and “Atlas Shrugged,” famously called herself a “radical for capitalism.” The libertarian writer and journalist Brian Doherty has borrowed the epithet for his remarkably engaging and encyclopedic history of the movement in “Radicals for Capitalism: A Freewheeling History of the Modern American Libertarian Movement” (Public Affairs, 768 pages, $35). As a senior editor for Reason magazine — the largest and most influential libertarian publication in the world today — Mr. Doherty is perfectly positioned to have researched and written this tome. Although the book is long and the typography dense, it’s is a page-turner, covering in delicious detail not only the big names (Friedrich Hayek, Ludwig von Mises, Ayn Rand, Murray Rothbard, Milton Friedman, Barry Goldwater, etc.), but the quirks and oddballs operating in the nooks and crannies of the movement, publishing low-circulation “freedom” magazines out of basements and sponsoring small seminars in hotel conference rooms.

I attended one of these seminars in 1981, when a close friend told me about Andrew Galambos, a retired aerospace engineer and physicist teaching private courses through the Free Enterprise Institute (hundreds of such organizations come and go throughout Mr. Doherty’s history), under an umbrella field he called “Volitional Science.” The introductory course was V-50. This was Econ 101 on freemarket steroids, an invigoratingly muscular black-and-white world where Adam Smith is good, Karl Marx is bad; individualism is good, collectivism bad; free economies are good, mixed economies bad.

Galambos’s course was popular in Orange County, Calif. (labeled by our neighbors in L.A. County as the “Orange Curtain”), and the time was right with President Reagan in office and conservatives on the ascendant. Where Rand advocated for limited government, Galambos proffered a theory in which everything in society would be privatized until government simply falls into disuse and disappears. Galambos identified three types of property: primordial (one’s life), primary (one’s thoughts and ideas), and secondary (derivatives of primordial and primary property, such as the utilization of land and material goods). To Galambos, capitalism is “that societal structure whose mechanism is capable of protecting all forms of private property completely.” To realize a truly free society, then, we have merely “to discover the proper means of creating a capitalist society.” In this free society, we are all capitalists.

Galambos’s story is not unusual in the history of this oft-fringy movement. He had a massive ego that propelled him to a successful career as a private lecturer, but led him to such ego-inflating pronouncements as his classification of all sciences into physical, biological, and his own “volitional sciences.” His towering intellect took him to great heights of interdisciplinary creativity, but often left him and his students tangled up in contradictions, as when we all had to sign a contract promising that we would not disclose his ideas to anyone, while we were also inveigled to solicit others to enroll. (“You’ve got to take this great course.” “What’s it about?” “I can’t tell you.”) And he had a remarkable ability to lecture for hours without notes in a colloquial style, but when two hours stretched into three, and three hours dragged into four, his audiences were never left wanting for more.

Most problematic, however, was any hope of translating theory into practice, which is where the rubber meets the road for any economic or political principle. Property definitions are all well and good, but what happens when we cannot agree on property rights infringements? The answer was inevitably something like this: “In a truly free society all such disputes will be peacefully resolved through private arbitration.” Sounds good in theory, but I would like more data from the real world. And, also typical of the movement, Galambos never published his long-promised book in his lifetime. Finally, in 1999, his estate issued Volume 1 of “Sic Itur ad Astra” (“The Way to the Stars”), a 942-page, $125 tome published by the Universal Scientific Publications Company, Inc. Galambos’s dream was to be a space entrepreneur and fly customers to the moon. According to his logic, in order to realize this dream he believed that society in its entirety had to be privatized first. Too bad Galambos did not live long enough to witness the space entrepreneur and libertarian Burt Rutan succeed in being the first to build a private rocket that reached space. It is a lesson libertarians should take to heart—we don’t need to do everything at once, and freedom is achieved one step at a time.

Another disturbing theme running throughout the libertarian movement, so well recounted by Mr. Doherty, is the sense that we are absolutely right. Absolute certainty generates absolute intolerance. One would think, for example, that Randian Objectivists would embrace other libertarians. But no, like the Baptists and Anabaptists, who warred over whether baptism should be implemented at birth or in adulthood, some of Rand’s biggest battles were fought not with socialists but with fellow libertarians. For example, libertarians disagree about foreign policy and the role of troops overseas, with some arguing that what other nations do is none of our business, while other libertarians hold that the protection of domestic property sometimes requires foreign intervention in a preemptive manner. Most commonly, libertarians rarely agree on the best strategy to bring about a free market society—through direct political activism within the system or by nonparticipation in hopes that the system will fall into disuse.

Barbara Branden, a close friend of Rand’s, recalled a dinner catastrophe that resulted from the first meeting between Rand, the libertarian economist Henry Hazlitt, and Ludwig von Mises, the greatest intellectual defender of freemarket economics of the 20th century. “The evening was a disaster. It was the first time Ayn had discussed moral philosophy in depth with either of the two men. ‘My impression,’ she was to say, ‘was that von Mises did not care to consider moral issues, and Henry was seriously committed to altruism. . . . We argued quite violently. At one point von Mises lost his patience and screamed at me.'” Economist and Nobel laureate Milton Friedman, one of the godfathers of libertarianism, recalled an incident at the first meeting of the Mont Pelerin Society in 1947, at which was gathered a veritable Who’s Who of free market economists (including himself, Hayek, Hazlitt, Mises, Fritz Machlup, George Stigler, and Frank Knight). “One afternoon, the discussion was on the distribution of income, taxes, progressive taxes, and so on. In the middle of that discussion von Mises got up and said ‘You’re all a bunch of socialists,’ and stomped out of the room.” Such moral absolutism leads to moral absurdities, and the libertarian movement has been plagued with the problem for the entirety of its history. Defining a movement with bullet points that require a commitment to the entire list before membership is conferred more often than not leads to lower membership rolls, and libertarians are more guilty than most at excommunicating those who deviate even slightly from the canon.

Ironically, I believe that the libertarian dream of free minds and free markets will come about not through the traditional channels of libertarian books, magazines, and seminars, or even through political action (the Libertarian Party is alive but organizing its members is like herding cats), but through the marketplace itself — the Wikification and Googlefication of the economy has turned every man and woman into a capitalist. EBay is the biggest retail outlet on the planet, and anyone can participate — you don’t need a state license or a government permit. Through the Internet, anyone can communicate and trade with anyone else, thereby bypassing traditional channels of state control over commerce. With the open access to knowledge that the Internet provides, it is only a matter of time before the government control of peoples’ lives becomes obsolete. At that point, we will have achieved something close to the libertarian dream.

Mr. Shermer is the publisher of Skeptic magazine,(skeptic.com), a monthly columnist for Scientific American, and the author of “Why Darwin Matters,” “The Science of Good and Evil,” “How We Believe,” and “Why People Believe Weird Things.”