Achieving AI-style reasoning without an LLM Minotaur, an AI architecture built on ELC by Fleeting Swallow, performs deduction, induction, abduction, diagnosis, belief revision and counterfactual reasoning with no language model and no GPU, using one operation on one network on a single ordinary processor core at about a quarter of a second per question. In blind tests written by people who never saw its code, Minotaur matched a current language model reasoning in words on a police interview where questions change the witness's memory, and on learning, diagnosing and predicting systems from their data alone. The company argues that language models inherit human reasoning weaknesses because they are trained to predict the next word of written thought, and that checkable, replayable reasoning was the goal of AI work for roughly sixty years before language models. Minotaur AI Deep Dive: Achieving Reasoning Without a Language Model In the last post we introduced Minotaur, an AI that reasons with no language model and no GPU. This post looks at why language models think the way people do, at what was tried before them and where each attempt stopped, and at how Minotaur’s brain does the same kinds of reasoning differently: not by imitating how people write their thinking down, but by working on the structure of the system it’s reasoning about. Introduction In the last post https://fleetingswallow.com/introducing-minotaur-a-gpuless-ai-architecture/ we introduced Minotaur , an AI architecture built on ELC that works out its answers by measuring rather than predicting. We showed it checking real regulations against records of how they were applied: finding which organisation broke a rule, by how much and where, and telling a broken rule from a badly recorded measurement. Checking rules against records is one kind of thinking. Today’s language models are admired for something broader: they can deduce, explain, diagnose, weigh a hypothesis, imagine what would have happened if things had been different, and change their minds when told something new. Can a machine with no language model, and no GPU, do all of that? The answer is yes: - Minotaur’s brain does the main kinds of reasoning usually credited to large language models: deduction https://en.wikipedia.org/wiki/Deductive reasoning , induction https://en.wikipedia.org/wiki/Inductive reasoning , abduction https://en.wikipedia.org/wiki/Abductive reasoning , diagnosis, seeing against doing, choosing the experiment that settles a question, revising a belief https://en.wikipedia.org/wiki/Belief revision , and reasoning about histories in which asking a question changes the answer. - It does all of them with one operation on one network , on one ordinary processor core, at about a quarter of a second per question on a described system. - On blind tests written by people who never saw its code, it matched a current language model reasoning in words, on a police interview where the questions change the witness’s memory, and on learning, diagnosing and predicting systems from their data alone. Why a Language Model Thinks Like a Person A large language model is trained to predict the next word of a piece of text. It learns this from an enormous amount of writing, from books, papers, textbooks, forums and code, by doing it trillions of times on thousands of GPUs. To predict the next word of a proof, you have to follow the proof. To predict the next line of a doctor’s notes, you have to follow the diagnosis. Much of the writing in the world is people thinking on paper, so a model that gets very good at continuing it ends up very good at imitating the thinking. That’s why simply asking a model to “think step by step” https://en.wikipedia.org/wiki/Prompt engineering makes its answers better. So a language model mirrors the way people think. It inherits our strengths: explaining, drawing analogies, using common sense, taking a question in ordinary words. Researchers have also found that it inherits our weaknesses. Like people, language models find a logical argument easier to accept when its conclusion sounds believable, and harder when it doesn’t. Their answers can shift with how a question is framed or the order things are put in. And like ours, its explanations are often written after the fact, not a record of how the answer was reached. The model never sees the world, only our words about it. It does mean that if you want reasoning that can be checked, replayed and certified, imitating the way people write their thinking down may not be the best place to start. Exact, checkable reasoning was what most approaches to AI before language models were trying for. Seventy Years of Trying Something Else People tried to build machines that reason for some sixty years before language models. Each attempt worked up to a point and then stopped, and where they stopped explains why we ended up with language models. Search and theorem proving In 1956 Allen Newell, Cliff Shaw and Herbert Simon built the Logic Theorist https://en.wikipedia.org/wiki/Logic Theorist , a program that proved theorems from Whitehead and Russell’s Principia Mathematica https://en.wikipedia.org/wiki/Principia Mathematica . Their next program, the General Problem Solver https://en.wikipedia.org/wiki/General Problem Solver , tried to do the same for any problem that could be written as a starting point, a goal and a set of moves. The idea was that reasoning is search: try the possible steps until you reach the goal. It worked on puzzles. On real problems the number of possible steps grows so fast that no computer could search them. In 1973 the Lighthill report https://en.wikipedia.org/wiki/Lighthill report to the British government named this the combinatorial explosion https://en.wikipedia.org/wiki/Combinatorial explosion , and funding in Britain was cut sharply. Expert systems The answer in the 1970s was the expert system https://en.wikipedia.org/wiki/Expert system , which gave the machine knowledge instead of search: hundreds or thousands of hand-written rules of the form if this, then that , collected from human experts. MYCIN https://en.wikipedia.org/wiki/Mycin , built at Stanford, recommended antibiotics for serious infections, and in a 1979 evaluation its advice compared well with that of specialists. XCON https://en.wikipedia.org/wiki/Xcon , at Digital Equipment Corporation, configured computer orders and saved the company a great deal of money. They stopped for two reasons. Every rule had to be got out of an expert’s head and written down by hand, which came to be called the knowledge acquisition bottleneck https://en.wikipedia.org/wiki/Knowledge acquisition . And they were brittle: just outside what the rules covered, the system had nothing sensible to say. By the end of the 1980s the market for them had collapsed. Logic programming Logic programming https://en.wikipedia.org/wiki/Logic programming aimed to have the machine reason exactly, in a proper logic. That was the bet behind Prolog https://en.wikipedia.org/wiki/Prolog , created in Marseille in 1972, and behind Japan’s Fifth Generation Computer Systems https://en.wikipedia.org/wiki/Fifth Generation Computer Systems project, which ran from 1982 to 1992 and was built around logic programming. Logic gives exact answers, and its descendants, the solvers https://en.wikipedia.org/wiki/SAT solver that check whether a set of conditions can all be true at once, are now used every day to verify computer chips. But logic only reasons about what someone has written down as logic. The world doesn’t arrive in that form, and the Fifth Generation project ended without the thinking machines it had promised. Hand-built common sense In 1984 Douglas Lenat https://en.wikipedia.org/wiki/Douglas Lenat started Cyc https://en.wikipedia.org/wiki/Cyc , an attempt to write down, by hand, the common sense that expert systems lacked: that water runs downhill, that people have mothers, that a thing can’t be in two places at once. Over the following decades its team entered millions of such facts. It showed how large the common sense people take for granted is, and that writing it down by hand never comes to an end. Probability and causal models From the late 1980s, led above all by Judea Pearl https://en.wikipedia.org/wiki/Judea Pearl , reasoning under uncertainty got a proper mathematical footing. A Bayesian network https://en.wikipedia.org/wiki/Bayesian network says which things affect which and how strongly, and lets a machine work out what an observation implies. Pearl went on to make precise the difference between seeing something and doing it https://en.wikipedia.org/wiki/Do-calculus : seeing a wet pavement suggests it rained, but hosing the pavement yourself tells you nothing about the weather. In the same years, Raymond Reiter, Johan de Kleer and Brian Williams turned diagnosis