And therefore I think the solution I have found for myself will be valid for all sincere men who set themselves the same question. First of all, to the question: What must we do? I replied to myself: I must not lie either to myself or to others, nor fear the truth wherever it may lead me. We all know what lying to other people means, and yet we lie unceasingly from morning to night: ‘Not at home,’ when I am at home; ‘Very pleased,’ when I am not at all pleased; ‘My respects,’ when I do not respect; ‘I have no money,’ when I have some, and so on. We consider lies to other people, especially certain kinds of lies, to be bad, but are not afraid of lying to ourselves; yet the very worst, most downright and deceptive lie to others, is as nothing in its consequences compared with that lie to ourselves on which we have built our whole life. That is the lie we must not be guilty of, in order to be able to answer the question: What must we do?
—Leo Tolstoy, What Then Must We Do?
“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, and it all comes from lying continually to others and to himself. A man who lies to himself is often the first to take offense. It sometimes feels very good to take offense, doesn’t it? And surely he knows that no one has offended him, and that he himself has invented the offense and told lies just for the beauty of it, that he has exaggerated for the sake of effect, that he has picked on a word and made a mountain out of a pea—he knows all of that, and still he is the first to take offense, he likes feeling offended, it gives him great pleasure, and thus he reaches the point of real hostility .”
—Father Zosima, in Fyodor Dostoevsky, The Brothers Karamazov