In the final chapters of the novel, he suffers a complete mental breakdown upon realizing that he can no longer deceive himself in this respect.
ɪnðə fˈaɪnəl tʃˈæptɚz ʌvðə nˈɑːvəl, hiː sˈʌfɚz ɐ kəmplˈiːt mˈɛntəl bɹˈeɪkdaʊn əpˌɑːn ɹˈiːəlˌaɪzɪŋ ðæt hiː kæn nˌoʊ lˈɑːŋɡɚ dᵻsˈiːv hɪmsˈɛlf ɪn ðɪs ɹᵻspˈɛkt.