Cleanup attempt   OK I have just given this a pretty serious overhaul keeping in mind comments on this talk page I believe I have covered most of the major concerns However it is far from complete At this point I think a casual reader would get a general sense of the concept and its different uses I have added citations wherever possible and Id like to see more published sources for quotations Please feel free to make additions or suggestions but lets try to keep this from becoming unreadable Thanks to all whose suggestions on this page were incorporated into this iteration