The purpose of this paper is to explore the semantics of metaphoric language in scientific contexts. According to the theory of metaphor advanced below, the benchmark of a metaphoric expression is the implicit transfer of semantic features across incongruous semantic fields. This transfer results in a conceptual variation of "meaning" in the receiving semantic field. Thus, the theory of metaphor rests on semantic field theory. Existing semantic approaches to metaphor are evaluated in Section 1. In Sections 2 and 3 an (...) alternative theory is introduced through an analysis of the mechanics of the feature transfer process followed by a discussion of some methodological cues for deciphering the metaphor's "meaning." As I explore in Section 4, this theory of metaphor explains how all metaphoric expressions are potentially literal depending on the general compliance of the community of speakers. Consequently, concept formation in scientific contexts is, in large measure, metaphoric. Finally, I argue in Section 5 that metaphoric concept formation is an essential aspect of scientific reasoning for the purpose of solving conceptual problems. (shrink)