Chris Lehmann in the Los Angeles Review of Books:
Mortality is not the sustained Socratic mediation on the human condition that the title might suggest. It is, rather, made up largely of just this sort of carefully reported, drily ironic dispatches from the sick country (or “Tumorland,” as Hitchens comes to call it) — meticulously recording both the physical symptoms of rapidly encroaching decay, and the feeble human effort to assimilate them into whatever semblance of a recognizably normal life may still remain. At its heart, this slender volume is a prolonged and painful study in cognitive dissonance, as the robust, high-living and (yes) terminally witty Hitchens records the galloping dissolution of his health and consciousness — the two things that humans almost have to take for granted in order to function in any reliable fashion. If, as Montaigne famously said (by way of Cicero) “to study philosophy is to learn to die,” Mortality is a crash course in lived philosophy, without benefit of abstraction or metaphysical speculation.