Judea Pearl explains ‘Why’: On machines and the brain's ability to reason
Even a machine with the most sophisticated program of the day cannot tell whether the cock crowing makes the sun rise (as was believed for centuries) or the other way around.
By TOM TUGENDPRESIDENT BARACK Obama signs the Daniel Pearl Freedom of the Press Act surrounded by the late journalist’s family at the White House in 2010.(photo credit: COURTESY PEARL FAMILY)
LOS ANGELES – To say that UCLA professor Judea Pearl is a man of many parts defines understatement.He is best known in academic, engineering and scientific circles as an intellectual pathfinder, a pioneer in the field of artificial intelligence and demolisher of long-accepted theories.In his recently released new book, The Book of Why: The New Science of Cause and Effect, Pearl and co-writer Dana Mackenzie hope to tell lay readers about a part of our brain they never knew had a label – our ability to reason about cause and effect – and the prospect of emulating this ability in machines.Journalists in this country and around the globe are most likely to recognize the names of Judea and his wife, Ruth, as the parents of Daniel Pearl and active leaders of the foundation bearing his name.Daniel Pearl was the Southeast Asia bureau chief for The Wall Street Journal who was kidnapped and beheaded by Islamic extremists while he was following a story lead in Pakistan in 2002. Rather than sinking into lifelong embitterment or swearing revenge, Judea and Ruth Pearl decided to channel the legacy of their son into a global organization to perpetuate Daniel’s ideals of free journalism, love of music and dialogue between East and West.If Judea Pearl devotes half his working time to his research and academic responsibilities, and half to the work of the Daniel Pearl Foundation, he also manages the mathematically difficult task of devoting another half as a vocal advocate of Israel and Zionism against their detractors at UCLA and academia in general.Judea Pearl, 81, was born in the fervently Orthodox Tel Aviv suburb of Bnei Brak, co-founded by his grandfather. He met his future wife when they were students at the Technion-Israel Institute of Technology, where both graduated with degrees in electrical engineering.In the 1960s, the Pearls arrived in the United States, where Judea earned graduate degrees at Rutgers University and the Polytechnic Institute of Brooklyn. In 1970, he joined the faculty of the UCLA School of Engineering Computer Science Department and drew early attention for his research in artificial intelligence (AI), the interaction between humans and robotic machines.IN THE early part of his career at UCLA, Pearl’s research focused on how machines could cope with uncertain information, the way humans do. Over the past three decades, he has concentrated on the field of causality, the unique ability of humans to understand cause-effect relationships.His awards for the latter research were capped in 2012 by the $250,000 Turing Award, popularly known as the “Nobel Prize in Computing.” The awards committee noted at the time that Pearl’s findings advanced such diverse fields as medical diagnosis, homeland security, genetic counseling, human reasoning and the philosophy of science.
In The Book of Why, Pearl argues that machines endowed with artificial intelligence, which can now best human opponents in Jeopardy or poker, are nowhere near their potential. The reason, Pearl noted in an interview, is that these machines lack one crucial aspect of human intelligence – the ability to link cause and effect. Even a machine with the most sophisticated program of the day cannot tell whether the cock crowing makes the sun rise (as was believed for centuries) or the other way around.For instance, the inability to link cause and effect explains the lengthy delay before the US surgeon general could connect cigarette smoking to lung cancer and to early death, Pearl said.The Book of Why describes a pathway through which learning machines can rise from their present ability to process masses of data to a higher ramp enabling them to deal with “what if” questions – such as how will our sales be affected if we double the price of a given product, or what effect will a given drug have on our patient.The third and highest level of machine intelligence would deal with “counterfactual questions,” The New York Times noted in a review of the book. At that level, intelligent machines could tackle questions such as what would have happened in a given situation if a different action had been taken, or if Hillary Clinton had been elected president instead of Donald Trump.“It is my deep belief that everything in human thought and intuition, including religion and the ability to distinguish between the plausible and the implausible, can be formalized so that computers can provide the answers,” Pearl said.Ruth and Judea Pearl conceived the creation of the Daniel Pearl Foundation the week after they were officially notified of the murder of their son. It would be dedicated not to mourning or revenge, but seek to create mutual understanding between East and West.WITH RUTH Pearl now carrying the primary responsibility for the running of the foundation, a partial list of its multifaceted programs includes fellowships for journalists from South Asia and the Middle East to intern at American newspapers, including the Jewish Journal and World Youth News; annual lectures by top reporters and scholars at UCLA and Stanford University; and dialogues to promote Muslim-Jewish understanding. Another program, World Music Day, has seen some 14,000 musical performances in 141 countries since its inauguration 16 years ago.“Energized by the spirit of one visionary journalist, these programs unite people around their common humanity and reinforce their determination to see humanity triumphant and evil defeated,” Judea Pearl commented.Pearl’s daily work schedule starts at midnight and continues through early morning, thus avoiding phone calls and other interruptions. Yet, in addition to his research, meeting his PhD students at UCLA and his work with the Daniel Pearl Foundation, he has one more self-imposed assignment – to defend Israel and Zionism on the UCLA campus and throughout the academic world.As a secular and liberal Jew, “I know the language and thought process of the political Left and can meet them on their own turf,” he said. Breaking academic etiquette, he has shown no reluctance to chastise fellow professors, especially in the UCLA History Department and its Center for Near East Studies, for what Pearl considers their “Zionophobic racism.”His targets also include American Jewish organizations that he believes focus too narrowly on surface manifestations of classical antisemitism to the exclusion of the Zionophobic face of modern antisemitism, while neglecting to narrate the miracle of Israel and Zionism.Above all, Pearl never forgets his link to the often bloody but always resilient journey of the Jewish people at all times and in all places.Addressing a 2006 briefing at the United Nations marking the International Day of Holocaust Remembrance, Pearl said: “As I stand before you, I represent three generations scarred by hate-based murders. My grandparents perished in a genocide that was [Pearl’s emphasis], I narrowly escaped a genocide that was meant to be (and failed in 1948), and my son fell victim to the murderous terrorism the world faces today, which targets people for the ethnic and cultural identities they represent.”
