 The subtraction strategy (Brown 1992) is an attempt to identify the narrow contents of a subject’s beliefs by considering all of the contents of the subject’s belief and subtracting those that are not narrow. The contents that remain must be narrow. More precisely, if a content of my belief is something I believe, then a narrow content of my belief is something that I believe and that is believed by every possible duplicate of me (possibly within some restricted class of worlds). I say “ordinary content” instead of “broad content” here, since the subtraction strategy presupposes that not all ordinary contents are broad.