Some stories in a future history series are set entirely within a single period of the fictitious history whereas others describe transitions between periods. Thus, Robert Heinlein's " 'It's Great To Be Back!' " describes aspects of life on Earth and the Moon in the early period of interplanetary travel whereas "If This Goes On-" presents the later transition from the Prophets to the Covenant. The first work presents a future society whereas the second presents a political transition and thus also advances the multi-story narrative. By this criterion, Isaac Asimov's Foundation series and James Blish's Okie series are entirely "political," not "social." (John W Campbell edited the Future History, Robots, Foundation and Okies but clearly did not impose any single perspective or approach on three different writers.)
The seven works in the Solar Union period of Poul Anderson's Psychotechnic History comprise a "political" tetralogy and a "social" trilogy. Because of a single story, "Cold Victory," we know, first, that the Psychotechnic Institute was suppressed after the successful Humanist Revolt of 2170 and, secondly, that the Institute remained suppressed even after the Humanists in turn had been overthrown. Thus, there are two political transitions in a single work. (Similarly, "If This Goes On-" informs us both that the Prophets had been wielding power and that they were overthrown.) A behind the scenes struggle to re-shape society preceded the Humanist Revolt, in "Holmgang," and succeeded it in "The Snows of Ganymede," when the Institute tried to make a comeback. Finally, the escalating social discord and continued political intrigue of "Brake" prefigured the later period called the Second Dark Ages. The Solar Union grew from the UN world government of the earlier History and was succeeded, after the Second Dark Ages, by the Stellar Union. Thus, the Solar Union is a major unifying political force in the History and the four works mentioned so far are a political tetralogy set within this period.
Anderson also set three "social" stories in the Solar Union period. "Quixote and the Windmill" addresses the Asimovian question: will robots cause unemployment? "What Shall It Profit?" addresses the Heinleinian question: what would be the consequences if some human lives were indefinitely prolonged? "The Troublemakers" addresses both the Asimovian question: can there be a science of society? and the Heinleinian question: can social stability be maintained inside a large multi-generation interstellar spaceship? The Asimovian questions are the bases of that author's Robots and Foundation series. The Heinleinian questions are the bases of the last two volumes of that author's five volume future history. Anderson, using the background of his first attempted future history, addressed the four questions in three stories and, of course, presented different answers.
Because of the rapidity of technological advances, the first robot is himself obsolescent, redundant and unemployed so that he is first resented, then either ridiculed or pitied, by economically redundant human beings. Organisms that are immortal only because they are sheltered underground from all radiation are a useless dead end, their existence concealed from the general populace, and they are not mentioned again in the series. This story makes its point but does not advance the series narrative. The science of society can be used to manipulate dissent and to prevent mutiny in the generation ship - although it cannot prevent the Humanist Revolt. Unlike robots, immortality and generation ships, the idea of an applicable science of society appears not just once in the History but is also the basis of the Psychotechnic Institute which is presented as a force for good in the earlier stories but then goes wrong. The Institute is less successful than Asimov's Second Foundation but is at least temporarily successful like the priestly psychodynamicists of Heinlein's Prophetic theocracy.
Social and political interact. Social division and dissent generate political conflict in the generation ship but this story does not contribute to the political development of the Solar Union and emphasizes how people live within the ship.
Anderson skilfully alternated between stories which advanced the narrative of the series and others which used backgrounds provided by the series to make one-off comments on wider issues and on ideas familiar from the works of other writers. My discussion of this series has two handicaps. First, "The Snows of Ganymede" was not included when the series was collected so I have not read it. Secondly, I have, I hope temporarily, mislaid Volume II, Cold Victory, which covers the Solar Union period. Readers of this article are invited to correct any lapses of memory on my part?