The echo began in some indescribable way to undermine her hold on life. Coming at a moment when she chanced to be fatigued, it had managed to murmur, "Pathos, piety, courage—they exist, but are identical, and so is filth. Everything exists, nothing has value." If one had spoken vileness in that place, or quoted lofty poetry, the [echo's] comment would have been the same — "Ou-boum."

A Passage to India (1924)