 A more restricted attempt at such an approach is Ilkka Niiniluoto’s (1993). According to Niiniluoto, the theoretical framework of technology as the practice that is concerned with what the world should be like rather than is, the framework that forms the counterpoint to the descriptive framework of science, is design science. The content of design science, the counterpoint to the theories and explanations that form the content of descriptive science, would then be formed by technical norms, statements of the form ‘If one wants to achieve X, one should do Y’. The notion of a technical norm derives from Georg Henrik von Wright’s Norm and Action (1963). Technical norms need to be distinguished from anankastic statements expressing natural necessity, of the form ‘If X is to be achieved, Y needs to be done’; the latter have a truth value but the former have not. Von Wright himself, however, wrote that he did not understand the mutual relations between these statements. Ideas on what design science is and can and should be are evidently related to the broad problem area of practical rationality—see this encyclopedia’s entries on  practical reason  and  instrumental rationality—and  also to means-ends reasoning, discussed in the next section.