This book (a collection of 12 papers) is a summary of Langacker's studies preceding that year. Langacker reacted against the prevailing view that language was a self-contained system that could be studied in isolation, that grammar was distinct from lexicon and semantics, and that the meaning of a sentence could be expressed in mathematical logic. Langacker believed that language cannot be separated from cognition, that semantics is about concepts, and that semantics analysis is conceptual analysis.

Noting that grammar is simply a way to refer symbolically to concepts, i.e. that grammar is a symbolic element, connecting phonology (the sounds of speech) and concepts, in Langacker's system, grammar is fundamentally and extension of the lexicon. Grammar is an "inventory of symbolic resources". Grammatical units have a meaning, just like the items of a lexicon have a meaning. This "meaning" cannot be just a truth condition or a combination thereof, because the meaning is related to the whole cognitive process of understanding/speaking language, i.e. to a cognitive domain. For example, the class of nouns refers to a kind of cognitive processing, and that is its meaning, whereas the class of verbs refers to a different kind of cognitive processing, and that is its meaning. And different classes of nouns (e.g., count nouns as opposed to mass nouns) refer to different kind of "noun" cognition. By the same token, an item in the lexicon (a word) refers to a kind of cognitive processing, which is its meaning.

Langacker admits only three kinds of units: semantic (the concepts), symbolic (grammar, lexicon, morphology) and phonological (the sounds). The symbolic units connect units of the other two kinds.

At the same time, the form used to construct that concept is also "meaningful". One can create a content using many different forms of language. Langacker used the (confusing) term "imagery" to refer to how content is structured. By definition, a grammar already forces constraints on the "images" that content can assume. Each grammar already limites the universe of imagery that is available to the language user.

The rest of the book details analyses of common constructs.