William James, Subjective Effects of Nitrous Oxide
“ At the same time the rapture of beholding a process that was infinite, changed (as the nature of the infinitude was realized by the mind) in to the sense of a dreadful and ineluctable fate, with whose magnitude every finite effort is incommensurable and in the light of which whatever happens is indifferent. This instantaneous revulsion of mood from rapture to horror is, perhaps, the strongest emotion I have ever experienced. ”
