Tran Duc Thao, a wise and learned scientist and an eminent Marxist philoso- pher, begins this treatise on the origins of language and consciousness with a question: "One of the principal difficulties of the problem of the origin of consciousness is the exact determination of its beginnings. Precisely where must one draw the line between the sensori-motor psychism of animals and the conscious psychism that we see developing in man?" And then he cites Karl Marx's famous passage about 'the bee and the architect' from Capital: ... what distinguishes the worst architect from the best of bees is...