Modern writing textbooks tend to offer no heuristics, treat heuristics as if they do not have different impacts on inquiry, or take the view that heuristics are ideologically neutral pedagogies. Yet theory about language demonstrates that ideological neutrality is impossible. Any use of language in attempting to represent reality will inevitably privilege some aspects of reality and slight others, producing what Kenneth Burke has labeled "terministic screens." Clearly heuristics, as linguistic devices, are terministic screens, directing writers' attention, encouraging them to explore a topic through certain particular perspectives rather than others. Paradoxically, their benefit is also their hindrance: they assist inquiry by directing students along some lines of inquiry, yet they simultaneously limit inquiry by excluding other possible lines of inquiry. Once writers recognize heuristics as ideologically bound, they must acknowledge that heuristics are not as interchangeable as their representation in textbooks suggest. An analysis and illustration of the ideologies of two heuristics, tagmemics and the pentad, using Burke's method of identifying and classifying ideologies, shows that heuristics do differ in what they consider at issue, and that those differences do affect what students will conclude about a subject. Rather than teaching students just one heuristic or implying to students that heuristics are neutral pedagogies (through flippant advice like "use whatever works") instructors should begin to teach heuristics more carefully, making their differences more explicit. (PRA)