Stanislaw Lem (Wikipedia).
I can only say that one of the Biggests has departed us. The world will miss him.
When I returned from my ERASMUS year in the UK, I helped to organize the first Science-Fiction congress of my University in Spain, and after much debate, I convinced the others so they were made honoring Stanislaw Lem , and the short-tale award was the 'Stanislaw Lem' Short Tale Award I Edition. The next year we followed suit, and Philip K. Dick, one of his favourite American writers, was the next, and then so on...
I have read his SF books many times over, but one of my favorite ones are Fiasko, and The Invincible. He was such an intelligent writer, thought provocking, filled with fine irony and a savoir-faire, he managed the black and the white of Humanity, and really Knew Better.
salue, magister! desideraueris et reminisceris