Visiting professor Bruce Thornton used ancient Greek political philosophy to criticize modern foreign policy at a talk Wednesday, titled “New World, Old Wisdom: Foreign Policy and the Classics.”

According to Thornton, classics and humanities professor at California State University, Fresno the modern world has adopted democracy from ancient Greek politics, but it takes a different approach to foreign policy. Thornton studies ancient Greece extensively in order to find implications for modern political science.

Until the 1800s, the majority of the world, including the ancient Greeks, operated with a realist approach to foreign policy, according to Thornton. He said the world now predominately takes an idealist approach to foreign policy.

The driving force of realism is the quest for power, not matters of principle, while idealism is the belief that through the use of international laws and agreements, all nations can work in harmony.

Thornton said he believes one of the most important parts of foreign policy is to understand what motivates people, and the motives of two countries are often different.

“The biggest mistake a diplomat can make is to sit across the table from someone and think that he thinks the same way,” Thornton said.

A CNN poll from September 2013 shows that 40 percent of Americans approve of President Barack Obama’s foreign policy approach. Thornton said he believes the U.S. should shift to a more realist mentality.

“Clearly, over the last five years American foreign policy has been a disaster,” Thornton said. “We have no credibility anywhere in the world.”

Thornton said international groups, such as the United Nations, are more problematic than beneficial.

“The United Nations is an abysmal failure,” Thornton said. “It’s an excuse … to hang out in Manhattan and not pay parking tickets.”

The talk was sponsored by the Clements Center for History, Strategy & Statecraft, the history department and the Thomas Jefferson Center for the Study of Core Texts and Ideas.

Steele Brand, a postdoctoral fellow at the Clements center, which started in 2013, said the center aims to bring more attention to the classical world’s politics.

“Our mission is to bring the insights of history to modern foreign policy,” Brand said.

The audience contained a mix of students and professors. Matthew Deal, a global policy studies graduate student who attended the speech, said it is important for political leaders to be informed by history.

“I think we can draw a lot of lessons [from the Greeks] and draw parallels with the origins of democracy,” Deal said.