In an examination of the conceptual knowledge basis of the human inferential capacity, object and event concepts are distinguished; and three types of semantic relations are established, based on manner of activation: autonomous, by similarity, and by association between events. Four operations on conceptual knowledge are relevant to inferences: accentuation and inhibition of features, derivation of structures from other structures, and the inversion of operations. A model of autonomous inferences differentiates these from controlled inferences in that the former are derived from neighboring knowledge domains, the latter from more distant domains. The basic structures of metaphors and analogies are described; phenomenologically, and a vector model is used to suggest the nature of the underlying neural process whereby the memory selects classifiable features from the sensory details of stimuli. (Copyright 1994, Sociological Abstracts, Inc., all rights reserved.) (J. Hitchcock in LLBA 1994, vol. 28, n. 3)