This is a great novel just as a sci-fi book.

But if you read it through the lens of 1960s communist-era Poland, it adds a layer of poignant political and philosophical commentary.

TLDR: under post-WW2 communism there was a huge emphasis on the superiority of socialism, and a narrative of evolution and conflict that will inevitably bring the advancement of society and the victory of communism - and that this struggle was a necessary crucible to forge this victory (e.g. dialectical materialism [0], etc).

But The Invincible throws a different light on it. Yes, you can have evolution, you can have wars, but all this doesn't have to lead to anything better. It can just produce a swarm of automatons that do their thing thoughtlessly, just following simple rules that have been programmed into them, and reflexively harming anything that gets in their way.

And the only way for a human being to survive in those conditions is to shield their thoughts, and pretend to just go with the flow, in order to avoid being targeted by the swarm.

This is a striking metaphor of life under communism, and what it takes for a human being to survive in it - the kind of a metaphor of which Lem was a master.

[0] https://en.wikipedia.org/wiki/Main_Currents_of_Marxism#Summa...