Modern thinking about the possibility
of intelligent systems all started with Turing's famous paper in 1950. He, of course, knew
that he couldn't define what intelligence was, so because of that, he introduced
what he called the Turing Test. The idea was that if a human couldn't tell
within five minutes if he was talking to a computer or a person, then the computer
would be said to have passed the Turing Test. Turing couldn't imagine the possibility
of dealing with speech back in 1950, so he was dealing with a teletype, but much
like what you would think of as texting today. And that was because Turing knew that he
couldn't actually define what intelligence was. It's too hard. It's too slippery. So
that's why he introduced the Turing Test. But I've read that paper many times and I
think that what Turing was really after was not trying to define intelligence or a test
for intelligence, but really to deal with all the objections that people had about why
it wasn't going to be possible. What Turing really told us, was that serious people can
think seriously about computers thinking and that there's no reason to doubt that computers
will think someday. That day is approaching. About 10 years after Turing published his paper
in 1950, important laboratories were set up by Marvin Minsky and John McCarthy, by Allen Newell
and Herbert Simon. McCarthy's approach at Stanford was to start with mathematical logic: he spent
his whole life trying to bend logic to his will. Newell and Simon focused on modeling human
thinking. They developed systems that solve simple puzzles and work out simple problems in
a manner that they believed was consistent with human experiments. Minsky's approach was harder to
characterize. He believed that one representation, method, or approach — no one of those could
deliver a full understanding of intelligence. That was the central message of his seminal
paper, which was titled "Steps Toward Artificial Intelligence", in 1961. You know, in retrospect,
we can think that Turing told us we could do this and that paper by Minsky told us what to
do. So that's why Turing and Minsky are often regarded as the real pioneers, the
real founders of the field of artificial intelligence. Well any event that brings us
to what some people call AI's first wave. Early in 1960s, James Slagle wrote a program that
integrated symbolic expressions. He was trying to model what a freshmen does at MIT when they learn
that kind of mathematics. Because Slagle's program performed so impressively, it's what I consider
to be the signature program of AI's first wave. That key idea was called 'problem reduction'. The
idea is simple: you just take a hard problem and you break it into simpler problems, and then you
break those simpler problems into problems that are still simpler until you've got something
you can just do. That's what problem reduction was about, but it's only one of a cornucopia
of ideas that have emerged from AI research. At MIT, the work of Slagle was quickly
followed by other successes, and by 1970 programs understood drawings, they learned from
examples, they knew how to build structures, and one even answered questions
much like Siri and Alexa do today.