Direct observations of behavior evoked by a fetish object (wet shoe) in one patient are reported. The intrinsic qualities of an object endowing it with fetish power are examined. Such qualities may be related to human perceptual preferences, a product of phylogeny, stemming from such factors as the primate interest in body parts and extracorporeal objects. The capacity to relate to an inanimate object including the assimilation of the object by varied motor acts reflects the crucial role of objects (tools) in hominid evolution. Also phylogenetically based is the human capacity to assign multiple meanings to an object.