 Multi-dimensional systems (Husserl 1913 [1962], §10; Ingarden 1960 [1964], Chapter 2; Thomasson 1999, Chapter 8; Smith 2007, Chapter 8) address the second worry to some extent by acknowledging that the different dimensions of categorization are possible, and that no one-dimensional list can purport to completeness. In principle, multi-dimensionalists may even accept that there is no fixed number or limit on how many one-dimensional lists of categories there may be, though each such list may purport to provide a unique, correct, exhaustive categorization of entities considered in the chosen respect.