This chapter develops a taxonomy of ways to think and talk about levels. Using an example from contemporary neuroscience — the multilevel mechanisms of spatial memory — it argues that ‘levels of mechanisms’ captures the central explanatory sense in which explanations in neuroscience (and elsewhere in the special sciences) span multiple levels. The multilevel structure of neuroscientific explanations is a consequence of the mechanistic structure of neuroscientific explanations. The importance of levels of mechanisms is emphasized by showing how other common notions of levels (such as levels of science, levels of theories, levels of control, levels of entities, levels of aggregativity, and mereological levels) fail to describe the explanatory levels appearing in the explanation for spatial memory.
Keywords: spatial memory, taxonomy, levels, neuroscientific explanation,