TOK@ISPrague

As global leaders remain divided on whether to carry out a military strike against Syria in response to the apparent use of chemical weapons against its people, Tim Harford looks at the different claims made about how many people have been killed. The United States, the UK and France are sharing intelligence, but all quote different estimates of how many people they think died in the attack by Syrian President Bashar al-Assad's forces. Tim speaks to Kelly Greenhill, a professor of political science at Tufts University in the US, and co-author of Sex, Drugs and Body Counts about why the numbers vary so widely. And he speaks to Megan Price from the Human Rights Data Analysis Group, who has been trying to keep a tally of the deaths in Syria since the conflict began.

"Consider the world that preceded the United Nations. The basic rule of that system, one that lasted for centuries, was that states had just cause to go to war when legal rights had been violated. Spain tried to justify its conquest of the Americas by saying it was protecting indigenous civilians from atrocities committed by other indigenous peoples. The War of the Austrian Succession was fought over whether a woman had a right to inherit the throne. The United States largely justified the Mexican-American War, including the conquest of California and much of what is now the Southwest, by pointing to Mexico's failure to pay old tort claims and outstanding debts. The problem with the old system was not that no one could enforce the law, but that too many who wished to do so could. The result was almost constant war."

"Eyesight can be improved-in some cases dramatically-through laser surgery or implantable lenses. Should a promising young baseball player cursed with normal vision be allowed to get that kind of corrective surgery? In this instance, Major League Baseball says yes. Major League Baseball also permits pitchers to replace the ulnar collateral ligament in the elbow of their throwing arm with a tendon taken from a cadaver or elsewhere in the athlete's body. Tendon-replacement surgery is similar to laser surgery: it turns the athlete into an improved version of his natural self. But when it comes to drugs Major League Baseball-like most sports-draws the line. An athlete cannot use a drug to become an improved version of his natural self, even if the drug is used in doses that are not harmful, and is something that-like testosterone-is no more than a copy of a naturally occurring hormone, available by prescription to anyone, virtually anywhere in the world."

"There's a natural back and forth: we think about things a particular way, which motivates experiments, which in turn provide data, which leads us to refine and revise the way we conceptualize phenomena and theoretical entities. This dance between theory and experimentation is common to all science. In the case of psychology, it is a particularly young field. It's early days for the empirical study of many core psychological phenomena, including happiness."