The word delusion appears in the following sentences from Moby-Dick:
Chapter 1 > Paragraph 13 > Sentence 1:
Though I cannot tell why it was exactly that those stage managers, the Fates, put me down for this shabby part of a whaling voyage, when others were set down for magnificent parts in high tragedies, and short and easy parts in genteel comedies, and jolly parts in farces—though I cannot tell why this was exactly; yet, now that I recall all the circumstances, I think I can see a little into the springs and motives which being cunningly presented to me under various disguises, induced me to set about performing the part I did, besides cajoling me into the delusion that it was a choice resulting from my own unbiased freewill and discriminating judgments.
Chapter 80 > Paragraph 3 > Sentence 1:
It is plain, then, that phrenologically the head of this Leviathan, in the creature's living intact state, is an entire delusion.
Concordance for the word delusion from Moby-Dick.