In this offering, it is time travel with a mission: to fix everything. Not too lofty, right? An institution has been created to oversee umm well, time, I guess. The ranks in the institute are Computer, which is a title, not a thing) who is a person in charge, Technician, one whom everyone hates because he is the one who actually physically makes the changes, Observers, Cubs, who are the trainees, and Maintenance, plus some other job descriptions. They are recruited out of their own ‘when’ to Eternity, which is timeless in that it is not located in any specific time. It’s job is to observe the various time periods and make changes to avoid the society at that time from doing anything that will create conditions which will destroy the species. They talk about going ‘upwhen’ and ‘downwhen’.
Asimov addresses some more futuristic issues, such as why almost all of the personnel in Eternity are male, (because males can be pulled out of their whens with almost no effect, whereas it would seem that removing females can have far far reaching effects. The personnel of Eternity are expected to be single, stay single, and be childless.
The story centers around Technician Harlan, who comes across one of the very rare females working in Eternity. He falls in love, and the rest of the book is about his actions as he endeavors to not be separated from her.
On the time line, there are Hidden Centuries:
… the time between the 70,000th and the 150,000[centuries].It was a subject that was rarely mentioned. It was only Harlan’s close associate with Twissel [a powerful ranking Computer] that accounted for his own small knowledge of the era. What it amounted to was that Eternals couldn’t pass into Time in all those thousands of Centuries. The doors between Eternity and Time were impenetrable. Why? No one knew.
It is about the development of the human species, evolution and unsuccessful space travel, attempted in many centuries, but always a failure.
Lots of science-y stuff, and quasi science-y stuff:
There is the question of the true nature of Reality, the question of the conservation of mass-energy during Reality Change and so on.
Why does Reality possess inertia? We all know that it does. Any alteration in its flow must reach a certain magnitude before a Change, a true Change, is effected. Even then, Reality has a tendency to flow back to its original position.
It is about risk-taking and risk-aversion. Do we do ourselves a disservice by always arranging things so that all pitfalls and miseries are averted? Asimov takes on that old saw: what doesn’t kill you makes you stronger. Is this true? Or can we constantly tweak ourselves away from problems and disasters and create an ideal species in an ideal society? Is Utopia actually achievable? We see this idea today in the criticisms of helicopter parents who never let their kids experience anything disappointing or negative.
– Everything is from a Western perspective. All of the observing and tweaking seem to be of the Western civilizations, as if the Eastern societies never existed.
– The idea that Woman is man’s downfall, and he just misses the Woman Is Evil Tempting Man trope by a hair.
– He, as it seems almost every sci fi writer prior to 2000, missed the digital era. Harlan is still searching what would appear to be Eternity’s version of microfiche for historical records and information.
All in all, a really good tale, with lots to think about. I did not find this 1955 book particularly dated, probably a tribute to the carefully handled details, which are just obscure enough to allow us to think what we will, although I am aware that other readers did find it dated.