Sentence:  "...I realize as never before how cheap and valueless a thing is <WSD>life</WSD>. <WSD>Life</WSD> seems a joke, a cruel, grim joke. You are a laughable incident or a terrifying one as you happen to be less powerful or more powerful than some other form of <WSD>life</WSD> which crosses your path; but as a rule you are of no moment whatsoever to anything but yourself. You are a comic little figure, hopping from the cradle to the grave. Yes, that is our trouble&mdash;we take ourselves too seriously; but Caprona should be a sure cure for that." She paused and laughed. 
Meaning of the word marked with <WSD> tags:  (en), "Existence"