It is evident that Swadesh has not only had much experience with basic vocabulary in many languages but has acquired great tact and feeling for the expectable behavior of lexical items. Why then this urge to include unstable items in his basic list? It is the urge to obtain a list as free of geographical and cultural conditioning as possible. And why that insistence? It is the hope of attaining a list of items of universal occurrence. But it is becoming increasingly evident that such a hope is a snare. Not that such a list cannot be constructed; but the nearer it comes to attaining universality, the less significant will it be linguistically. Its terms will tend to be labile or vague, and they will fit actual languages more and more badly.

The practical operational problem of lexicostatistics is the establishment of a basic list of items of meaning against which the particular forms or terms of languages can be matched as the medium of comparison. The most important quality of the meanings is that they should be as definable as possible. In proportion as meanings are concrete, we can better rely on their being insulated and distinctive. An elephant or a fox or a swan or a cocopalm or a banana possess in unusually high degree this quality of obvious, common-sense, indubitable identity, as do an eye or tooth or nail. They isolate out easily, naturally, and unambiguously from the continuum of nature and existence; and they should be given priority in the basic list as long as they continue to show these qualities.