If political differences are destined to leave us divided and friendless, how do you explain the life of Joel Fox?

Fox died on January 10 after more than a decade of living with cancer. He was California’s most prominent taxpayer advocate since Howard Jarvis, for whom he worked, and whose anti-tax organization he led from 1986 to 1998. Fox, a Republican, advanced conservative ideas on TV and op-ed pages. He advised the campaigns of Gov. Arnold Schwarzenegger, Mayor Richard Riordan, and U.S. Sen. John McCain.

That profile, in our polarized times, might make you think Fox was one of those political ideologues who are driving the country apart. But the opposite is true.

Fox, more than any person in California politics, built deep relationships with people across the political spectrum. And he did not do this through consensus or compromise. Instead, Fox built friendships on disagreement itself—a warm, open, and curious style of disagreement.