This is why the analysis of language, from Lancelot to Destutt de Tracy, is conducted on the basis of an abstract theory of verbal signs and in the form of a general grammar: but it always takes the meaning of words as its guiding thread; it is also why natural history manifests itself as an analysis of the characters of living beings, and why, nevertheless, the taxonomies used, artificial though they may be, are always intended to unite with the natural order, or at least to dissociate it as little as possible; it is also why the analysis of wealth is conducted on the basis of money and exchange, but value is always based upon need.