“One thing alone troubles me: the fear that I may do something which man’s constitution disallows, or would wish to be done in some other way, or forbids till a future day.” 
“For we know that the law is spiritual; but I am of the flesh, sold into slavery under sin. I do not understand my own actions. For I do not do what I want, but I do the very thing I hate. Now if I do what I do not want, I agree that the law is good. But in fact it is no longer I that do it, but sin that dwells within me. For I know that nothing good dwells within me, that is, in my flesh. I can will what is right, but I cannot do it. For I do not do the good I want, but the evil I do not want is what I do. Now if I do what I do not want, it is no longer I that do it, but sin that dwells within me.” 
“Man’s greatness comes from knowing he is wretched: a tree does not know it is wretched. Thus it is wretched to know that one is wretched, but there is greatness in knowing one is wretched.” 
“My dog doesn’t worry about the meaning of life. She may worry if she doesn’t get her breakfast, but she doesn’t sit around worrying about whether she will get fulfilled or liberated or enlightened. As long as she gets some food and a little affection, her life is fine. But we human beings are not like dogs. We have self-centered minds which get us into plenty of trouble. If we do not come to understand the error in the way we think, our self-awareness, which is our greatest blessing, is also our downfall.” 
 Marcus Aurelius (trans. Maxwell Staniforth), Meditations, Book VII, No. 20.
 Romans 7.14–20 (NRSV)
 Blaise Pascal (trans. A.J. Krailsheimer), Pensées, frag. 397.
 Charlotte Joko Beck, “Beginning Zen Practice” in Everyday Zen.