4 ideas
Don Sindulfo García, a Zaragoza scholar, builds the anacronópete, an iron ship that travels against the current of time. His schemes collapse at every stop, and the whole voyage is finally revealed to be a dream.
In the novel, going back through time does not merely move people. It unwinds their bodies, so passengers grow younger in proportion to the years crossed and could shrink toward infancy or cease to exist. Sindulfo therefore has to invent a protective fluid that shields his travellers from time's reversal. That makes the machine's first engineering problem the travellers' own biology, not the destination.
Each era the travellers reach proves cruder, more violent or more absurd than its legend. Nostalgic belief in a purer earlier age, where women were obedient or wisdom was intact, collapses on contact with the real thing. The novel uses time travel to test and puncture idealized history rather than to celebrate it.
Sindulfo's breakthrough machine serves petty private aims: possessive jealousy and a wish to escape modern social change. The book argues that scientific power does not ennoble its user. It simply lets his existing vanities and fears act on a larger stage, where they fail more spectacularly.