For a man who proudly described himself as “simple,” Barry Goldwater remains a historical puzzle. Recent accounts have portrayed him as both the founder of the modern Republican Party and an ideal from which it has strayed, as a representative of the civil interpersonal politics of an earlier generation and an example of its rhetorical extremity, as an anti-intellectual Westerner and the philosopher-king of the Right.

When faced with a conflicted legacy, readers can only return to the original texts and form judgments for themselves. In inaugurating its James Madison Library in American Politics with a new edition of “The Conscience of a Conservative” (160 pages, $14.95), Princeton University Press has provided this opportunity. The series’ editor, Princeton historian Sean Wilentz, asserts that its goal is to combat “a decline in our collective recall and understanding of the ideas and events that have shaped American politics.” A careful reconsideration of Barry Goldwater’s radical conservatism is a useful place to begin.

When Goldwater published “The Conscience of a Conservative” in 1960, he had only recently emerged as a figure on the national stage. His first Senate term was marked by the neophyte’s deference, but as it drew to a close in 1958 he began to differentiate himself more sharply from President Eisenhower and his congressional peers. By 1960, he was openly referring to New York Governor Nelson Rockefeller’s moderate Republican supporters as the “Me-Tooers” and publishing a syndicated column on conservative principles that was carried by more than 100 newspapers nationwide.

At the urging of supporters, Goldwater cobbled together “The Conscience of a Conservative” — with the assistance of ghostwriter L. Brent Bozell — from past speeches and articles, and the final product at times reflects its fragmented origins. His voice, however, resonates throughout with a startling force and clarity. “For those of us wandering in the arid desert of Eisenhower Republicanism,” Pat Buchanan later recalled, “it hit like a rifle shot.” Within five years, the book had sold over three million copies and initiated a transformation in the Republican Party that catapulted him to the head of the 1964 Republican ticket.

The book’s central achievement lay in Goldwater’s inversion of the conventional understanding of the relationship between material goods and spiritual fulfillment. From the progressive era through the Fair Deal, politicians who combated economic redistribution were accused of prioritizing cold financial logic over concern for their fellow human beings’ most fundamental needs. In “The Conscience of a Conservative,” Goldwater confidently asserted that it was in fact liberals who regarded “the satisfaction of economic wants as the dominant mission of a society.” The Welfare State, he argued, “transforms the individual from a dignified, industrious, self-reliant spiritual being into a dependent animal creature without his knowing it.” Goldwater emphasized the dignity of the self-sustaining, and in doing so portrayed progressive redistribution as both elitist and debasing.

Prior to Goldwater’s emergence on the national stage, conservatives had struggled to integrate their support for economic freedom into a holistic and politically resonant worldview. With these words he boldly resuscitated the argument that economic freedom supported, rather than constricted, the ability of the average citizen to live a spiritually fulfilling existence. “The Conscience of a Conservative” made laissez-faire, long marginalized by Hoover’s perceived failings and the trauma of the great depression, populist again.

The power of his message was furthered by its peculiar admixture of apocalyptic gloom and naïve optimism. Goldwater laced his dark cynicism about the social trajectory of the 1960s with an enduring faith in the dynamic potential of unhindered human ingenuity. This message was perfectly calibrated to appeal to Americans’ perpetual intuition that their political structure has strayed from its original goals, as well as our equally persistent willingness to believe that the resultant problems will — with old-fashioned effort and imagination — one day finally recede. This conflicted jeremiad formed the core of Republican rhetoric in the decades that followed.

In a dueling Foreword and Afterword, George Will and Robert Kennedy Jr. try to situate Goldwater in relation to those subsequent decades. Where Mr. Will implies that the modern Republican Party derives in large part from Goldwater’s ideas, Kennedy berates onetime Goldwater acolytes who have “turned today’s conservatism from a coherent philosophy into a series of veiled justifications for expanded government and corporate power.” With all their differences, these two commentators find an ironic common ground in the person of Goldwater himself: He was, they agree, a decent and genuine man, and his politics were based on an earnest and carefully developed interpretation of his world.

The gentility of their treatments of Goldwater is itself a reflection of the dulling wrought by the passage of time. As a man Goldwater stoically refused to personalize his politics, and his autobiography is filled with fond reminiscences of nostalgic drinks with the aging President Johnson and thoughtful dinner debates with Nelson Rockefeller. He maintained this refusal, however, against the unrelenting contrary efforts of his contemporaries. One need only watch the classic Lyndon Johnson campaign spot, in which a small girl counts daisy petals leading down to the explosion of an atomic bomb, to remember how intensely controversial Goldwater was in the context of his era.

A consideration of John Kenneth Galbraith, whose “The New Industrial State” (Princeton University Press, 576 pages, $24.95) has been simultaneously released by the James Madison Library, provides a reminder of Goldwater’s radicalism in the early 1960s. Galbraith worried deeply about the alignment of interests between corporate power and the individual citizen, and envisioned a dense net of reforms to redress the systemic failures he identified. Whereas “The New Industrial State” proposed to safeguard freedom through continued vigilance and action, Goldwater sought a dramatic rollback on even those interventions already in place. As a result Galbraith spent the 1964 election delivering stark warnings, before a large and sympathetic audience, of Goldwater’s “warlike tendencies” and his “commitment to a revolt of the affluent against the poor.” Whether or not one accepts this grim assessment of Goldwater’s transformative ideas, it is hard to controvert the wryly tragic conclusion offered in Galbraith’s memoirs: “Goldwater was a man before his time.”

Mr. Burgin, a graduate student in the history department at Harvard University, last wrote for these pages on Joseph Schumpeter.