This study examines whether the categories ANIMATE/INANIMATE: might be formed on the basis of information available to the cognitive system. We suggest that the discrimination of percepts according to these categories relies on proprioceptive information, which allows the perceiving subject to know that he is 'animate'. Since other 'objects' in the world exhibit movements, reactions, etc. similar to those that the subject experiences himself, he can 'project' his knowledge onto these objects and recognize them as 'animate' like himself. On this basis we try to corroborate the empricist position in the debate concerning the organization of knowledge as opposed to the nativist view. Furthermore, we argue that the categorical dichotomy ANIMATE: /INANIMATE: is more basic than other analogous ones such as LIVING: /NON-LIVING: , BIOLOGICAL: /NON-BIOLOGICAL: and we sketch a 'categorical stratification' following the line 'humans-animals-plants' based on the hypothesis that humans detect different degrees of 'vitality' according to the degree of similarity they recognise between the considered instance and themselves.