 Moreover, this move would come at the price of building a sort of atomistic materialism into the very notion of reduction; if we were to define reduction in mereological terms, it would be conceptually impossible that parts reduce to the whole they form. However, it seems possible (though, in the light of science, maybe highly unlikely) that in some cases parts do not exist over and above the whole they form. Such was the view of certain historical varieties of holistic idealism (see for example entry on  F.H. Bradley),  and some have argued it is true of quantum systems including entangled particles (Silberstein 1999). Thus if we were to tie the notion of reduction to mereology, it would not be general enough to capture the full range of possible reductionist positions.