Titus Oates was once a name every schoolboy knew. Oates was the disgraced Church of England clergyman who, in 1678 and 1679, accused various English Catholics of a "popish plot" to assassinate King Charles II and take control of the government of England.

 On the basis of the testimony of Oates and a few other similar characters, more than a dozen Catholics were found guilty and executed. Priests were arrested and held indefinitely, and Catholics were excluded from Parliament.

 Then, as the trials went on, it became clear that Oates' detailed charges were all lies. His name became a synonym for liar. Lord Justice Scroggs, who had sentenced several of Oates' targets to death, turned on him: "I wonder at your impudence that you dare to look a court of justice in the face, after having been made to appear so notorious a villain."

 Joseph Wilson is our latest Titus Oates. Wilson is the former diplomat who traveled to Niger to check out whether Saddam Hussein's Iraq was trying to buy nuclear materials there and who wrote an article for The New York Times in July 2003 asserting that he had found there were no grounds for believing that.

 A few days later, columnist Robert Novak reported that Wilson's wife, Valerie Plame, was a CIA official who had helped send him on this mission. That sparked an outcry that someone in the government had blown Plame's cover as a covert agent in violation of a 1982 law.

 A special prosecutor was appointed to investigate. In September 2003, Wilson said, "It's of keen interest to me to see whether or not we can get Karl Rove frog-marched out of the White House in handcuffs." He wrote a book called "The Politics of Truth," which got rave reviews from the mainstream press, and he became a foreign policy adviser to John Kerry's campaign.

 But Wilson, like Oates, lied. His Times article said he had been sent by the CIA at the request of Vice President Dick Cheney. But Cheney denies he made any such request, and former CIA Director George Tenet said the trip was initiated inside the agency.

 Wilson's article said George W. Bush lied in his 2003 State of the Union Address when he said that British intelligence reported that Iraq had sought to buy uranium in Africa. But Wilson's mission covered only one country, and the British government has stood by its report.

 Moreover, the report that Wilson sent the CIA said that Iraq had sought to buy uranium in Niger in 1998, unsuccessfully; agency analysts concluded, not unreasonably, that this strengthened rather than weakened the case against Saddam. Continued...