Since haecceities like being Napoleon and being identical to Socrates are properties uniquely tied to specific individuals, haecceitistic differences are naturally explained in terms of differences in the distribution of haecceities. These properties, sometimes called “thisnesses” or “individual essences”, are typically thought to have the existence of the relevant individuals as a necessary and sufficient condition for their instantiation. So, for example, if Napoleon exists, then, necessarily, exactly one thing, Napoleon, instantiates being Napoleon and, if Napoleon does not exist, nothing instantiates being Napoleon. In addition, facts about the distribution of other non-qualitative properties—e.g., being five feet from Napoleon—are necessitated by the distribution of haecceities and qualitative properties. (Here, talk of ‘properties’ should be interpreted in the broad sense including monadic properties as well as \(n\)-adic relations.) Most haecceitistic differences will therefore involve differences in the distribution of haecceities as well as additional non-qualitative properties like being five feet from Napoleon.