... it's theoretically possible to delete a whole directory with a single typo. As a precaution, consider working through this section with administrator privileges turned off for your account, ... point is that you wind up with two identical files in the same directory with different names. Just remember to add a backslash before a space if you want to name the copy with two words (Thesis\ ... worry about extended attributes; the Mac always keeps them together with their associated files. When you're working with files on the command line, however, you have to be more cautious....