QUOTE : On the other hand, when nature has shown even the slightest dithering or fuzziness in making its boundaries, different cultures have far more sway over the division of concepts than anyone exposed only to the conventions of one society would imagine. Of course, concepts must be based on some sensible logic and internal coherence if they are to be both useful and learnable. But within these limits, there are still many ways of dissecting the world that are perfectly sensible, perfectly learnable by children, perfectly suitable for the communicative needs of the speakers -- and yet totally different from what we are used to.