 Scientific reduction became an important topic in the philosophy of science within the context of a general interest in the unity of science, and it was inspired by specific alleged cases of successful reductions. The most prominent argument against reductionism stems from the observation that straightforward reductions hardly ever occur. Hence, reductionism cannot be regarded as yielding a coherent picture of what actually goes on in science. As long as reductionism is supposed to be more than a purely metaphysical position and is intended to say something significant about scientific change or norms, the value and relevance of the notion of reduction seems to depend in part upon how well the reductionist positions fit the facts, which their critics argue they do not (see, for example, Sarkar 1992; Scerri &amp; McIntyre 1997).