Sir Winston Churchill was one of the most impressive individuals to serve as Prime Minister of the United Kingdom. His political ideology, leadership style, writings, personal views, and artistic ability have been extensively studied by great biographers, including Sir Martin Gilbert, Roy Jenkins, William Manchester, Henry Pelling, and Andrew Roberts.

Yet, like other leaders before and after him, there remain little nuggets of information about Churchill that haven’t been thoroughly analyzed. One such is the importance of friendship in Churchill’s personal and political career.

That’s what makes John von Heyking’s Comprehensive Judgement and Absolute Selfishness: Winston Churchill on Politics as Friendship a new and vital component of Churchillian study. A professor of political science at the University of Lethbridge in Canada, von Heyking is the author of several books—including, notably, one on friendship as defined by Aristotle and Plato. In his view, Churchill’s “concern for friends and for friendship always seems to hover above, or in the background, of his statecraft and in his thinking about statecraft and politics.” Comprehensive Judgement and Absolute Selfishness “brings that background into focus” and proves that “friendship plays a central role in [Churchill’s] moral vision of politics.”

Churchill regarded friendship as part of his statecraft, and “sought the virtue-friendships that Aristotle describes of those who exercise the highest moral and intellectual character.” This included prime minister David Lloyd George, Lord Beaverbrook (Max Aitken), and U.S. president Franklin Delano Roosevelt. They may not have always agreed with his political philosophy, but all played a crucial role in building the great man into a great leader.

“When he made friends,” writes von Heyking, “they were very close friends who were pivotal for his political success.” They often resembled the “types of character who could serve as allies with whom to fight political and military battles, but also as companions with whom to enjoy the greatest action and dramas that life has to offer.” The ultimate political outsider, Churchill created lasting friendships from both sides of the political aisle. This helps explain his long-term membership in the “Other Club,” a private dining society that brought left-leaning, right-leaning, and non-ideological people together during sessions of parliament.

Von Heyking notes Churchill “saw a connection between political prudence or phronesis and conversation and friendship.” His conversations with friends wouldn’t have necessarily established winners and losers—and one assumes they probably concluded with a fair amount of agreeing to disagree. That said, mastering this fine art created additional political benefits for the prime minister. Being a good conversationalist “enables one better to exercise political prudence that sees the variability of nature and its conflicting circumstances, and to tolerate its smudging.”

Von Heyking analyzes Churchill’s “magnanimous capacity”—his ability to “forgive injustices and insults against him.” This characteristic defined his political career from start to finish. Churchill’s magnanimity is also associated with the “flame of Christian ethics,” he mentioned in a 1948 speech, despite his ambiguous relationship with Christianity. Von Heyking devises a unique tie-in with the Munich crisis—including Churchill’s famous Sermon on the Mount comparison to then-prime minister Neville Chamberlain that highlighted his “meekness and humility”—and correctly notes that Christian ethics wasn’t in conflict with Churchill’s desire to defeat Adolf Hitler and bring an end to the Nazi regime.

Another intriguing component of the book is the examination of Churchill as a “classical prince” with respect to parliamentary and/or liberal democracy. His friendships are not generally juxtaposed with his role as a parliamentarian, but they did aid him during the Second World War and in building his War Cabinet. Churchill needed the support of the Labour Party—and, more critically, its support among labor unions—to ensure that production flourished and military equipment was properly constructed. He maintained a good friendship with Labour MPs as well as party leader Clement Attlee, despite their obvious political differences. His ability to navigate murky political waters with a friendly demeanor and strength of character served him well during World War II.

Comprehensive Judgement and Absolute Selfishness also focuses on the evolution of Churchill’s friendships with prominent individuals.

His friendship with Beaverbrook was a “political alliance” that both helped with the war effort and transcended the “game of politics.” They were great communicators, loved to tell stories, and genuinely enjoyed each other’s company. In von Heyking’s analysis, the two men shared “the kind of friendship that Aristotle calls sunaisthesis that is the very characteristic of human life: ‘this would come through living together and sharing conversation and thinking; for this would seem to be what living together means in the case of human beings.’”

In contrast, Churchill and Roosevelt “enjoyed each other and enjoyed the script of world history they both wrote and were written upon.” They had different political ideologies, goals, and strategic visions, which wouldn’t naturally make them the best of friends. Von Heyking suggests they were virtue-friends, which seems like an accurate assessment; these two great-souled men “formed and sustained their mutual work and alliance, and even…weld[ed] their two nations’ military staffs into a single operational unit.”

The key to Churchill’s political success was his ability to build strong, long-lasting bridges of friendship with logical political allies and illogical political opposites. In doing so, he created his own little marketplace of ideas to use as both a sounding board and a means of defending his politics and principles. His successful use of friendships as an agent of statecraft is clearly defined in John von Heyking’s well-written book, which adds yet another dimension to a masterful political leader.