 Work in Artificial Intelligence (AI) has produced computer programs that can beat the world chess champion, control autonomous vehicles, complete our email sentences, and defeat the best human players on the television quiz show Jeopardy. AI has also produced programs with which one can converse in natural language, including customer service “virtual agents”, and Amazon’s Alexa and Apple’s Siri. Our experience shows that playing chess or Jeopardy, and carrying on a conversation, are activities that require understanding and intelligence. Does computer prowess at conversation and challenging games then show that computers can understand language and be intelligent? Will further development result in digital computers that fully match or even exceed human intelligence?  Alan Turing  (1950), one of the pioneer theoreticians of computing, believed the answer to these questions was “yes”. Turing proposed what is now known as  ‘The Turing Test’:  if a computer can pass for human in online chat, we should grant that it is intelligent. By the late 1970s some AI researchers claimed that computers already understood at least some natural language. In 1980 U.C. Berkeley philosopher John Searle introduced a short and widely-discussed argument intended to show conclusively that it is impossible for digital computers to understand language or think.