Lexicography is the science that undergirds the preparation of diction
aries as lists of words and phrases whose meanings are defined on the
basis of semantic analysis. By contrast, Onomantics reverses this para
digm: it identifies concepts that are related to each other and need t
o be represented as important tools in the production and organization
of knowledge. Terminology bridges these two approaches: it draws heav
ily on the lexicographic model while moving stolidly toward an onomant
ic framework - from a semantic focus on the meanings of words to an on
omasiological concern with the identification and representation of co
ncepts. The article is the first of a Two Part sequence in which the b
asic concepts and the rationale of Onomantics are identified. They pro
vide a framework for enhancing the ability of Terminology to contribut
e to Knowledge Organization. The essential logic of Onomantics as the
science of concept representation is explained and its general relatio
nship to Terminology as a growing but mixed field of applications is d
iscussed.