 In the following we aim at a critical survey of mereology as standardly understood, so we shall mainly confine ourselves to theories that do in fact accept the antisymmetry postulate along with both reflexivity and transitivity. However, the above considerations should not be dismissed. On the contrary, they are crucially relevant in assessing the scope of mereology and the degree to which its standard formulations and extensions betray intuitions that may be found too narrow, false, or otherwise problematic. Indeed, they are crucially relevant also in assessing the ideal desideratum mentioned at the beginning of this section—the desideratum of a neat demarcation between core principles that are simply meant to fix the intended meaning of ‘part’ and principles that reflect more substantive theses concerning the parthood relation. Classical mereology takes the former to include the threefold claim that ‘part’ stands for a reflexive, transitive and antisymmetric relation, but this is not to say that “anyone who seriously disagrees with them had failed to understand the word” (Simons 1987: 11), just as departure from the basic principles of classical logic need not amount to a “change of subject” (Quine 1970: 81). And just as the existence of widespread and diversified disagreement concerning the laws of logic may lead one to conclude that “for all we know, the only inference left in the intersection of (unrestricted) all logics might be the identity inference: From A to infer A” (Beall and Restall 2006: 92), so one might take the above considerations and the corresponding development of non-classical mereologies to indicate that there may be “no reason to assume that any useful core mereology […] functions as a common basis for all plausible metaphysical theories” (Donnelly 2011: 246).