Carl von Clausewitz, the Prussian philosopher of war, wrote in the early nineteenth century that “courage is of two kinds: first, physical courage, or courage in the presence of danger; and next, moral courage, or courage before responsibility.” The late U.S. Senator John McCain demonstrated both. His physical courage was apparent during the 23 combat missions he flew over North Vietnam, especially the last of these, when he was shot down over Hanoi, severely wounded, and captured by the North Vietnamese. During his captivity over the next five and a half years, more than two of which he spent in solitary confinement, he demonstrated not only physical but also moral courage while enduring the worst possible forms of torture. Perhaps his most courageous act as a prisoner of war came when he refused to accept early release, in order to remain with his fellow Americans and deny the North Vietnamese a propaganda victory.

Years later, McCain would continue to demonstrate moral courage. He often broke with his party and never adapted his political positions to the latest opinion polls. He refused to attack the character of his political opponents, even as political competitions across the country reached new depths of incivility.

McCain’s unwillingness to callously disparage his rivals was rooted in his empathy for his fellow man. At a time when American public discourse was becoming increasingly insular, he sought to foster relationships with like-minded nations and understand conflicts abroad that affected U.S. security and national interests. His fast-paced overseas trips, always with bipartisan groups of colleagues from the U.S. Senate and House, were legion. During my many meetings with him and his dear friends Senator Lindsey Graham and Senator Joseph Lieberman, McCain always tried to understand the wars in Afghanistan and Iraq from the perspective of the Afghan and Iraqi people. Empathy lay at the root of his humaneness, including his opposition to any form of torture.

Psychologists tell us that empathy and humor are linked. The senator’s quick wit, usually delivered in the form of self-deprecating jokes or well-meaning barbs aimed at allies and opponents alike, were the foundations on which he built friendships across the aisle and internationally. These qualities, combined with his boundless energy, allowed him to generate bipartisan support for otherwise contentious proposals, from campaign finance reform to defense appropriations to immigration reform.

Perhaps McCain’s most dramatic act of empathy was his push to normalize relations between the United States and Vietnam. In 1994, he co-sponsored a bill with then Senator John Kerry that called for an end to economic sanctions against Vietnam. McCain went on to visit the country over 20 times. This week, his former tormentors praised and thanked him. Retired Vietnamese Colonel Tran Trong Duyet, who, as commandant of the place that American prisoners of war called the Hanoi Hilton, oversaw the systematic torture and deprivation of McCain and his fellow servicemen, recalled McCain’s “toughness and strong stance.”

That toughness and strong stance derived, in part, from McCain’s pride in his nation and his sense of honor as a naval officer in its service. He wrote in his farewell letter:

I lived and died a proud American. We are citizens of the world’s greatest republic, a nation of ideals, not blood and soil. We are blessed and are a blessing to humanity when we uphold and advance those ideals at home and in the world. We have helped liberate more people from tyranny and poverty than ever before in history. We have acquired great wealth and power in the process.

McCain’s pride in what the United States stands for in the world drove his efforts as a senator for over 30 years to free people from oppression and promote representative government based on individual rights, liberty, and the rule of law. It also made him determined to ensure that the United States succeeded in the great competitions of his era. In his oversight role on the Senate Armed Services Committee, he advocated for a strong, ready military as the best guarantor of peace. Even when it had become unfashionable to do so, he called for strategies in Afghanistan and Iraq that would allow the United States to win those wars and secure its vital interests. In 2006 and 2007, when many were calling for a withdrawal from Iraq, McCain pressed for a renewed military effort and a new plan of action to ensure the enduring defeat of international terrorist organizations and deny Iran the ability to extend its malign influence across the region. His push for victory had a moral dimension: McCain believed that sending American troops into harm’s way is justified only if those troops are enabled to achieve outcomes worth the risks they run and the sacrifices they make.

McCain was equally strong in his determination to combat Russian President Vladimir Putin’s campaign of propaganda, disinformation, and political subversion against the United States and Europe. He was zealous in his defense of democracy and his condemnation of autocracy. His passion sometimes gave rise to his famous temper. But that temper was always directed at those who threatened what he held so dear—the freedom, liberty, and humaneness denied him for over half a decade in a prisoner-of-war camp.

Although McCain’s memory evokes words such as courage, empathy, pride, and determination, it will be up to the senator’s fellow citizens and like-minded friends abroad to translate those words into actions that secure his legacy. Will we find the courage to confront those who perpetuate ignorance and foment hatred and deploy it to justify violence against the innocent? Will we exhibit the empathy necessary to understand each other, build partnerships, and, when we disagree, do so respectfully? Will Americans rekindle pride in who they are, one nation committed to the principles of liberty, individual rights, and the rule of law? Will the United States possess the determination not only to defend its way of life but also to strengthen its democratic institutions and promote freedom and prosperity at home and abroad? Although McCain is no longer here to help us answer these questions, we must draw inspiration from his memory—and honor it with deeds that secure the legacy of an American hero.