Appearances to the mind are of four kinds. Things either are what they appear to be; or they neither are, nor appear to be; or they are, and do not appear to be; or they are not, and yet appear to be. Rightly to aim in all these cases is the wise man's task. Discourses

A man who lies to himself, and believes his own lies, becomes unable to recognize truth, either in himself or in anyone else, and he ends up losing respect for himself and for others. When he has no respect for anyone, he can no longer love, and in him, he yields to his impulses, indulges in the lowest form of pleasure, and behaves in the end like an animal in satisfying his vices. And it all comes from lying — to others and to yourself. The Karamazov Brothers

One way to explain the complexity and unpredictability of historical systems, despite their ultimate determinacy, is to note that long chains of causation may separate final effects from ultimate causes lying outside the domain of that field of science. Guns, Germs And Steel

Never be ashamed,’ he said. ‘Accept what life offers you and try to drink from every cup. All wines should be tasted; some should only be sipped, but with others, drink the whole bottle.’ ‘How will I know which is which?’ ‘By the taste. You can only know a good wine if you have first tasted a bad one.’ Brida