[6] The essays take as their subject matter his fear of losing the ability to write, the torture of chemotherapy, an analysis of Nietzsche's proclamation that "what doesn't kill you makes you stronger," the joy of conversation and the very meaning of life.

[7] The critical response to Mortality was largely positive with friends and admirers of Hitchens praising both his character in confronting his death and the way that this was transferred onto the page.

He wrote that it was "sobering and grief-inducing to read this brave and harrowing account of his "year of living dyingly" in the grip of the alien that succeeded where none of his debate opponents had in bringing him down."

[8] Colm Tóibín fondly wrote in The Guardian of his experiences with Hitchens, opining that "he was the best company in the world" and offered praise for Mortality, writing that "in this book he does everything to make sure that his voice remains civilised, searching and ready to vanquish all his enemies, most notably in this case the dullness of death and its silence.

He hints, rather, at a fear of losing himself, of becoming an imbecile, someone who might, in terror and pain, say something foolish or (God forbid) religious near the end, to give his enemies satisfaction.