Set in the relatively near future (of 1948), "The Mechanical Answer" takes place on a re-nationalized Earth. Joseph Kayden, a citizen of the United States of North America, is the Director of Automatic 81, a factory that produces "portable tele sets." The huge facility is really a massive assembly line manned by robotic machines that require only one employee to run it: Joseph Kayden. Located outside of Albuquerque, Kayden lives on-site with his wife Jane, and as the story opens, Jane is in tears after she has heard the news that Joe has been reassigned to a super-secret project in Poughkeepsie, known generally as "The Thinking Machine." Jane is crying because she can't come.
Joe is considered "one of the practical boys" from the Department of Civilian Production, and the Thinking Machine -- known officially as the Project to Develop a Selective Mechanical, Numerical, Semantic and Psychic Integrator and Calculator -- has gone through four years of work without a breakthrough. The most recent Director was forced into retirement after the stress nearly drove him nuts, and Joe knows the consequences of failure are great, but he believes it's his duty to go when called. His unhappiness over not being able to bring Jane with him goes deeper than simple marital separation: Jane is his thinking companion as well, providing a right brain to his left (he calls it "horse sense"). "They don't know it," he tells her, "and I don't think you do either. But by myself I couldn't have done these things ... You've made me see things about this place I'd never have seen by myself ... You've brought the simple outlook of a child to this problem and all I've ever done is take your direct ideas and put them into shape. They don't want me, they want us."
But all they get is Joe, who relocates and begins learning about the Thinking Machine Project. The goal is to create a machine that can "duplicate the processes of the human mind." So far all they've been able to produce is one with "the mental processes of a four-year old child, emotionally unstable, with a limited I.Q. for its years." MacDonald's description of the facility is so 1950's:
"The Project was housed in a series of long, one-story buildings surrounded by a high electrified wall. Interception rocket stations were set up in profusion in the surrounding countryside, the scanners revolving perpetually. One building housed the best approach to a Thinking Machine that had been devised ... The main room was five hundred feet long and about eighty feet wide. All along the walls stood independent units of the machine. Each unit was plastered with switchboard panels, plug sockets and lamp indicators. Between the interstices of the panels showed an array of electronic tubes, circuit elements, relays."
Joe meets the scientist in charge, a German ex-pat named Dr. Zander, who is initially condescending and resists Joe's new ideas and input. Joe's communication with Jane is limited to letter writing, and after months of failure and dead ends, he is at his wit's end. Jane's heavily censored letters begin sounding odder and odder until Joe shows one to his assistant, who instantly recognizes that she has written a kind of code, mentioning things like "engrams," "frontal lobes" and "synthesis." Jane's "horse sense"dawns on Joe and the project changes direction. Jane has suggested aping the processes of the human mind by forming basic engrams, simple ones at first, becoming more and more complex until rational thought is possible. After many more months of re-working, Dr. Zander poses a single question to the newly-configured machine: "What hath God wrought?"
Filled as it is with long technical passages on the inner workings of the machine and how the human mind was thought to work, "The Mechanical Answer" seems at times to be more of a historical curio than an engaging story about people, at least to the non s-f fan. Still, it zips along in typical MacDonald fashion. The plot twist of having Jane's input bring about the "eureka!" moment in the plot is loudly broadcast in the first few pages, and the only real suspense here is the answer to the question posed to the machine. As Greenberg wrote in his introduction to the story, "It is ... one of the most optimistic stories ever written about the implications of artificial intelligence."
MacDonald would take this idea and rework it several months later, with far superior results. In "A Child is Crying," the Thinking Machine is replaced by a highly gifted child who, at the young age of seven, is able to run rings around the best scientists of his day. The answer the child gives at the end of that story, however, is far more pessimistic than the one we hear in "The Mechanical Answer."