within a research programme into its "negative heuristics", i.e., what research methods and approaches to avoid, and its "positive heuristics", i.e., what research methods and approaches to prefer. While the "negative heuristic" protects the hard core, the "positive heuristic" directs the modification of the hard core and auxiliary hypotheses in a general direction. Lakatos claimed that not all changes of the auxiliary hypotheses of a research programme (which he calls "problem shifts") are equally productive or acceptable. He took the view that these "problem shifts" should be evaluated not just by their ability to defend the "hard core" by explaining apparent anomalies, but also by their ability to produce new facts, in the form of predictions or additional explanations. Adjustments that accomplish nothing more than the maintenance of the "hard core" mark the research programme as degenerative. Lakatos' model provides for the possibility of a research programme that is not only continued in the presence of troublesome anomalies but that remains progressive despite them. For Lakatos, it is essentially necessary to continue on with a theory that we basically know cannot be completely true, and it is even possible to make scientific progress in doing so, as long as we remain receptive to a better research programme that may eventually be conceived of. In this sense, it is, for Lakatos, an acknowledged misnomer to refer to "falsification" or "refutation", when it is not the truth or falsity of a theory that is solely determining whether we consider it "falsified", but also the availability of a less false theory. A theory cannot be rightfully "falsified", according to Lakatos, until it is superseded by a better (i.e. more progressive) research programme. This is what he says is happening in the historical periods Kuhn describes as revolutions and what makes them rational as opposed to mere leaps of faith or periods of deranged social psychology, as Kuhn argued. Pseudoscience According to the demarcation criterion of pseudoscience proposed by Lakatos, a theory is pseudoscientific if it fails to make any novel predictions of previously unknown phenomena or its predictions were mostly falsified, in contrast with scientific theories, which predict novel fact(s). Progressive scientific theories are those that have their novel facts confirmed, and degenerate scientific theories, which can degenerate so much that they become pseudo-science, are those whose predictions of novel facts are refuted. As he put it: "A given fact is explained scientifically