There are 2 basic controversies concerning how metaphors are processed. First, are metaphoric mappings more akin to literal comparisons or to literal categorizations? And second, is metaphor comprehension indirect or direct? We believe that these controversies are more appqent than real and that a unified theoretical framework can be offered that reconciles these opposing views. The central idea is that all metaphors involve structural alignment of the target and base domains. Whether these alignments are more akin to comparisons or to categorizations, and whether they are computed directly or indirectly, depends on 2 factors: the type of representation invoked by the base term and the linguistic form of the metaphor.Metaphors establish mappings between concepts from disparate domains of knowledge. For example, in the metaphor "The mind is a computer, " an abstract entity is described in terms of a complex electronic device. It is widely believed that metaphors are a major source of conceptual change. In the field of cognitive psychology, the computer metaphor resulted in a new way of conceptualizing the mind and has inspired researchers to postulate a vast array of mental constructs. Indeed, it has recently been claimed that metaphors may be the primary (if not the only) mechanism for reasoning with abstract concepts-metaphors allow us to structure vague or ambiguous ideas in terms of more concrete realms of experience (e.g