When one thinks about free speech in America, certain images and feelings come immediately to mind. For some it may be the halls of Congress, or city hall. For some it might be the famous painting by Norman Rockwell depicting speech as one of the "Four Freedoms." For others it might be the protestors in New York's Zuccotti Park, unbowed for months as they raised their collective voices against corruption and corporate greed.

Such images bring to mind the more positive attributes of freedom of speech in America. The ability to speak out and to have your voice heard, whether you're the president of a Fortune 500 company or an unemployed autoworker, is one of the most fundamental rights guaranteed by our democracy. As essential as the right to breathe, the bedrock commitment to the right of free speech and assembly sets the United States apart from much of the rest of the world.

But there is another element that has played an important role in sustaining our First Freedom, one that has ensured the stability and viability of our democracy in the best of times. I'm speaking of civility, and civil dialogue.

In a country that thrives on a diversity of views, America is at our level best when we are able to listen to each other civilly, to respectfully disagree with those with whom we do not see eye to eye, and to speak clearly against those views we find abhorrent.

But civility, especially in politics, has fallen by the wayside in recent years, the victim of partisan politics and divisive appeals to hatred and even bigotry. The ugly politics of division and hatred have at times taken our national discourse hostage. This threatens to undermine our civil society and our ability to function as a democracy through reasoned debate and compromise.

In the absence of civility and civil dialogue our society is diminished. When we engage in offensive or even hateful attacks of the kind we have seen in debates over some of the most important policy issues facing our nation today and when more rational discussion of policy gives way to shouting matches at town hall meetings or leads to physical attacks, our democracy suffers. Our dignity suffers when name-calling, epithets and threats against public officials and candidates for office replace thoughtful and reasoned dialogue.

We deviate from the path of civility when our leaders are condemned, not for their ideas, positions or policies -- but based on some perceived religious, ethnic or racial difference.

Civility suffers when otherwise well-meaning ordinary Americans take to heart some of the conspiracy theories that have circulated in recent years, such as rumors that the Obama administration is conspiratorially working to undermine the right to bear arms, or that the 9/11 attacks were orchestrated by Jews or Israel, or that the Federal Emergency Management Agency is setting up "concentration camps" for homeless Americans. Civility suffers when myths and conspiracies flourish on the Internet, where they gain credibility for no other reason than that they exist on a technological platform and can be read on a screen, then worm their way into our public discourse.

We see civility suffer when, in the debate over immigration reform, Hispanic Americans and other immigrants are vilified with racist or hateful stereotypes and are beaten and killed, or when protestors show up at anti-immigrant rallies with signs equating our national political leaders and the U.S. government itself to Hitler and Stalin.

Divisive appeals to hatred undermine the strength of our democracy and are an abuse of our fundamental freedoms.

We should be concerned, as we enter another presidential election season, that hateful words and rhetoric are going to escalate again as they have in previous campaigns. The gloves will fly off as the candidates seek to score political points and pander to their bases. Civility and civil dialogue will suffer.

How can we foster the kind of civility in public discourse that rejects appeals to bigotry, racism and prejudice and allows debates on the issues of the moment to be thoughtful and reasoned?

I would argue that it begins with our elected leaders and the candidates for office.

The personal attacks, the hateful rhetoric, the calls to bigotry and appeals to violence must stop. Regardless of whether the issue is the economy, healthcare, immigration or the national debt, we need to rise above the hateful rhetoric and to encourage advocacy that is vigorous but never personal or hostile.

It is time that we demand of our elected leaders and those seeking higher office to show true leadership by being the first, not the last, to reject the appeals to bigotry, racism and prejudice.

I also believe it is incumbent on each of the presidential candidates to avoid playing the politics of division and exclusion, especially when it comes to expressing religious beliefs on the campaign trail. When the candidates make their professions of faith a game of political one-upmanship, or insist their religious tradition makes them the better candidate for America, civility is lost and some Americans will invariably feel excluded.

We can, and must, do better.