Ifs Quotes (page 128)
If once a man indulges himself in murder, very soon he comes to think little of robbing; and from robbing he comes next to drinking and Sabbath-breaking, and from that to incivility and procrastination. Once begun upon this downward path, you never know where you are to stop. Many a man has dated his ruin from some murder or other that perhaps he thought little of at the time.
Thomas de Quincey
If it is asserted that civilization is a real advance in the condition of man? and I think that it is, though only the wise improve their advantages? it must be shown that it has produced better dwellings without making them more costly; and the cost of a thing is the amount of what I will call life which is required to be exchanged for it, immediately or in the long run.
Henry David Thoreau