Logic Theorist Explained – Everything You Need To Know

Updated: April 16, 2024 by History Computer Staff | Leave a comment

4 Facts About The Logic Theorist

It created better proofs than human mathematicians.
Its creation birthed fields of study like Artificial Intelligence and heuristic programming.
Its invention necessitated the creation of the Information Processing Language (IPL).
The Logic Theorist beat human mathematicians Alfred North Whitehead and Bertrand Russell as it offered better and more detailed proofs of their theorems.

Logic Theorist History

The inspiration for the Logic Theorist was sparked by various moments of pure scientific epiphany between the three collaborators, notably Herbert Simon, Allen Newell and to a lesser degree Cliff Shaw (more on him below).

The idea for the Logic Theorist was sparked in the early 1950s when Simon was consulting RAND Corporation. He saw a printing machine that printed out maps using ordinary letters, digits, and punctuation as symbols during his time there.

This piqued his mind as he realized that a machine could manipulate symbols and simulate decision-making and possibly attain the level of human thought. That was to be the genesis of automated thinking.

The program which had sparked Simon’s mind had been written by Newell, a RAND Corporation scientist studying logistics and organization theory. Newell was stimulated by a presentation he had watched in 1954 about pattern matching. At that moment, he realized that the interaction of a programmable unit, although simple, could accomplish more complex behavior, which included the intelligent behavior of human beings.

Logic Theorist History — Herbert Simon (left) and Allen Newell (right)
©Paolo Massa, CC BY-SA 2.0, via Wikimedia Commons – License

In 1955, Simon and Newell had discussions on the possibility of teaching machines to think. These discussions birthed a program that could prove mathematical theorems like in Alfred North Whitehead and Bertrand Russell’s Principia Mathematica. It was to be specifically engineered to mimic the problem-solving prowess exhibited by real people. The result was to be a program that could think like a proper human mathematician. However, to get the program running, Simon and Newell would need the help of a computer programmer.

To write the codes, Newell enlisted the help of John Clifford Shaw, a computer programmer from RAND, to develop the program. Cliff Shaw wrote the codes for the logic theorist using an early version of IPL (Information Processing Language), a programming language running on a computer of RAND’s Santa Monica research facility. By 1956, the Logic Theorist was finally ready for use. However, the perfect opportunity to really show the invention to the world would present itself in a few months after its making.

When the Logic Theorist was being built, the field of AI did not exist and was just coined by John McCarthy during the summer of 1956 for a conference organized at Dartmouth College in collaboration with Marvin Minsky and Claude Shannon. At the conference, Simon and Newell presented their invention, which was accepted. Later on, Simon confides: “They didn’t want to hear from us, and we sure didn’t want to hear from them: we had something to show them! In a way, it was ironic because we already had done the first example of what they were after; and second, they didn’t pay much attention to it”.

So, while McCarthy and his team were brainstorming the possibility of Artificial Intelligence, Simon, Newell, and Shaw were already recording breakthroughs in the same field.

Logic Theorist: How it worked

The Logic Theorist was built to mimic the brain prowess of human mathematicians, proving mathematical theorems like the ones in Russell and Whitehead’s Principia Mathematica. It proved 38 of the 52 theorems in the second chapter of the book and offered more detailed proofs than Russell and Whitehead.

Logic Theorist: Historical significance

The Logic Theorist remains a breakthrough in the history of science. The Logic Theorist was a pioneering force in Artificial Intelligence, heuristic programming, and computer programming. While computer programming was already existing at the time the invention was made, AI and Heuristic programming were not.

The logic theorist also ventured into the area of the search tree, having the root as the initial hypothesis, with each branch as a deduction based on the rules of logic. The aim of everything was the goal which was found somewhere in the tree. This was the proposition that the program was trying to prove.

The implementation of the Logic Theorist on a computer led to the development of a programming language called the Information Programming Language (IPL). This programming language used the same symbols that McCarthy adopted in creating his programming language, known as the LISP Programming language. This language is still relevant among researchers in the AI Circles.

The breakthrough of the Logic theorist also has significance in the world of philosophy. In Simon’s words, “[We] invented a computer program capable of thinking non-numerically, and thereby solved the venerable mind-body problem, explaining how a system composed of matter can have the properties of mind.” This raised questions about the possibility of machines having minds. This school of thought was later named Strong AI by philosopher John Searle. This argument still rages in various philosophical circles today.

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The image featured at the top of this post is ©Paolo Massa, CC BY-SA 2.0, via Wikimedia Commons.

Frequently Asked Questions

When Was Logic Theorist Invented?

The Logic Theorist was invented in 1956.

Who invented Logic Theorist?

The Logic Theorist was invented by the joint efforts of Herbert Alexander Simon (1916-2001), Allen Newell (1927-1992), and John Clifford Shaw (1922-1991) in 1956, making it the first artificial intelligence program ever. Each person brought their expertise and knowledge to the table to help create the Logic Theorist.

Herbert Alexander Simon, an American political scientist, sociologist, psychologist, and economist, had many studies, including cognitive psychology, philosophy of science, computer science, cognitive science, political science economics, sociology, management, and public administration.

Simon was a very influential social scientist with almost a thousand highly cited publications. Primarily focusing on decision-making within organizations, Simon is best known for his theories that won him the Nobel Memorial Prize in Economic Sciences in 1978, the “bounded rationality” and “satisficing” theories. He spent most of his career at Carnegie Mellon University. His consultation at RAND sparked his contributions to the invention of the Logic Theorist.

Allen Newell was a RAND Corporation researcher. As a pioneer in the Artificial Intelligence (AI) field, his expertise was in computer science and cognitive psychology. He also studied under Herbert Simon at Carnegie Mellon University’s school of computer science and the Department of Psychology, Tepper School of Business. Allen was also the first president of the American Association for Artificial Intelligence (1979-80).

Some of his most outstanding contributions include his work in Information Processing Language (IPL) in 1956, The Logic Theorist (1956), and the General Problem Solver (GPS) in 1957. He worked on the last two with Herbert Simeon.

Some of the outstanding awards he received in his lifetime include the ACM’s A.M. Turing Award (received along with Hubert Simon) in 1975 and the U.S. National Medal of Science (1992).

John Clifford Shaw, considered the father of the JOSS language, was a systems programmer at the RAND Corporation. He is pivotal in the invention of the linked list, a fundamental invention in many strands of modern computing technology. Newell enlisted him to write the codes for the Logic Theorist and joined with Simon and Newell in the development of the Information Processing Languages (IPL I through IPL V). he was also involved in the invention of the General Problem Solver (GPS).

What did the Logic Theorist do?

The Logic Theorist was the first human invention that could think at the human level, the first machine of Artificial Intelligence. It was built to mimic the solving skills of human mathematicians, making it the genesis of heuristic programming. It could prove mathematical theorems like the ones used in Russell and Whitehead’s Principia Mathematica.

It proved 38 of the first 52 theorems in the second chapter of the Principia Mathematica. Its proof for one of the theorems was so detailed that it was better than the proof produced by Russell and whitehead.

How was the Logic Theorist created?

The Logic Theorist was the product of collaborative efforts from Herbert Simon, Allen Newell, and John Shaw. The invention happened as the three men who were experts in their respective fields came together to create the first heuristic machine.