The Conceptual Base of Psychohistory
Seldon’s science of psychohistory is presented in a way so as to invite parallels with the gas laws of physics. The Other Wiki explains it as such. “Asimov used the analogy of a gas: An observer has great difficulty in predicting the motion of a single molecule in a gas, but with the kinetic theory can predict the mass action of the gas to a high level of accuracy.”
In one sense, large aggregates of random things can be more predictable than an individual random thing. The average of a thousand dice-rolls is less random than a single dice-roll. The behaviour of a large number of molecules is more predictable than the motion of one molecule. We can say so because it’s a valid assumption to make that the extreme results mostly cancel each other out. In a tank of gas, the random movements of all the gas molecules tend to cancel each other out.
The assumptions of the ideal gas laws (at least those that can be compared to psychohistory) are simple. There are a large number of identical monoatomic molecules moving about in random directions. All these molecules follow Newton’s Laws of motion. Collisions between molecules are perfectly elastic. These imply the ideal gas law that every high-school physics student knows, that pV = nRT. And in psychohistory, all humans are similar enough for individual variations to matter little. Human nature is mostly constant, and the way that people interact with each other hasn’t changed now.
Of course, the standard gas laws don’t always work, because of the inaccuracy of the assumptions, and physicists have had a greater understanding of gases since the 19th century, with things like statistical mechanics and Avogadro’s correction to the gas laws. And as a well-read scientist, Asimov surely must have known this.
What Asimov is trying to do here is to make an analogy with humans. In some ways, an aggregate of humans is more predictable than a single human. Of course, we do know that it can work in some cases. There’s a reason that pollsters use large samples of people.
While some people might feel rather offended analogizing humans to models of bouncing rubber balls, there really isn’t anything that bad with it. The main issue with psychohistory, however, is that random eccentricities don’t really cancel each other out. Societies are complex systems, and the butterfly effect means that small changes in the system can cause large effects.
This, of course, implies the existence of a Second Foundation of psychologists, even without any Mule to throw the Plan off course. Even without any unexpected elements, errors would compound over time, and events will begin to deviate from their course. This requires a set of protectors - the psychologists of the Second Foundation, who have the Plan - to correct for any deviations from the Plan. Indeed, Seldon does make a cryptic comment to Gaal Dornick about the Four Kingdoms, implying that the secession that sparks off the first crisis of the Foundation was engineered by the Second Foundation to happen on time.
Another implication is that this would imply a strict crackdown of transhumanism, both in the remnants of the old Empire and in the Foundation itself. This could probably be a reason that the Second Foundation wouldn’t want to have robots, even without the cultural descent from the Settlers from Elijah Bailey’s time. Any sorts of human enhancement must be heavily restricted, unless under the purview of the Second Foundation and their mentalic powers.
To top it off, Seldon and the Second Foundation use the science of psychohistory to figure out the general trend in history and basically insert in the First Foundation to cause an important enough change to have downstream effects. The Seldon Plan is what is supposed to happen, and any deviations from it, caused by mutants or accumulated random error are corrected by the psychologist-psychics of the Second Foundation.
Foundation and Robots
Isaac Asimov linking his Robot and his Foundation stories in Foundation's Edge is probably the biggest Broken Base issue among his fans. Both psychohistory and the Three Laws of Robotics don’t seem compatible at first glance, and it’s easy to dismiss it as Asimov trying to make money off a Robots/Foundation crossover in his older years.
But even if it is a cash grab, there are some thematic similarities between the two that make Canon Welding more understandable. Both come out from a very Golden Age environment and ethos, and both the Foundation stories and the Robot stories have similar structural similarities. This is somewhat obscured by the fact that the Foundation stories are collected and marketed as novels, while most of the Robot short stories are collected in short story collections like The Complete Robot.
Both sets of stories have a speculative element with strict rules as to how it works (the Three Laws and psychohistory), and both involve twisting convolutions of the basic assumptions of both. Another connection between the two is that the need for psychohistory is born out of the Three Laws, as Giskard points out in Robots and Empire. The Zeroth Law is a natural outgrowth out of the First Law, as human life would flourish best if humanity does. But as Giskard points out, any half-way competent robot would need some sort of psychohistory so as not fizz out from the uncertainty. Gregory Benford, in a group interview with Greg Bear and David Brin holds ‘‘control’’ to be the primary focus of Asimov’s work with robots and Galactic Empires. The Robot novels are about the control of robots and their relation with humans and explore how such control can break down or go out of control. The Foundation stories flip it, concerned with the control of humans themselves, by perhaps not very human Seldon Plan.
