Above all, do not lie to yourself. A man who lies to himself and listens to his own lie comes to a point where he does not discern any truth either in himself or anywhere around him, and thus falls into disrespect towards himself and others. Not respecting anyone, he ceases to love, and having no love, he gives himself up to passions and coarse pleasures, in order to occupy and amuse himself, and in his vices reaches complete bestiality,1 and it all comes from lying continually to others and to himself.2
1 By bestiality, Dostoevsky refers to “human predatoriness, and godless egoism.” Ronald D. Leblanc Times of Trouble: Violence in Russian Literature and Culture, http://bit.ly/1BYSjLF; Elsewhere in The Brothers Karamozov, Dostoevsky says, “People talk sometimes of bestial cruelty, but that’s a great injustice and insult to a beast; a beast could never be so cruel as a man, so artistically, artfully cruel.”
2 (Dostoevsky 2002 edition, 44)
Dostoevsky, Fyodor. The Brothers Karamozov. New York: Farrar, Straus and Giroux, 2002 edition.