By the time we have become fluent speakers of our native languages, we have learned to use thousands of words and phrases to refer to mental states and processes of ourselves and others. This richness in vocabulary parallels the complexity of the commonsense psychological model that defines the deep lexical semantics of these linguistic expressions. By studying the richness of psychological language, we learn about the various facets of the knowledge representation challenge, and its overall breadth of scope.

In this chapter, we attempt to catalog the full breadth of English words and phrases related to commonsense psychology. We organize this vocabulary into twenty-nine representational areas, and group words and phrases into lists of entries that we consider to be conceptually synonymous. Undoubtedly we have missed quite a few expressions, and we have not attempted to list every synonym or morphological variation. Instead, our goal is specifically about breadth of coverage and granularity of conceptual distinctions. In creating these word lists, we are defining the target of our knowledge representation efforts. Our task is to develop a set of formal theories of commonsense psychology in which all of these words have a referent, and in which the theories themselves are rich enough to distinguish between each enumerated concept. We concede that there are subtle differences between words and phrases that we have grouped into a single enumerated concept. However, we believe that the concept categories capture much of the meaning of each group of expressions, and give us a good starting point for future efforts to articulate (formally) subtle differences in meaning.

In offering this (long) catalog here, we hope to achieve several goals. First and foremost, we can think of no better way to show readers the enormous breadth of commonsense psychology in terms that are already well understood. Second, we see these list as a non-technical index to the topics that are formalized in Part III of this book. Where readers are interested only in certain topics of commonsense psychology, one need only to find the relevant concepts in these lists and consult the corresponding logical formalization. Third, these lists invite alternative formalizations of commonsense psychology, providing a starting point for those that want to pursue radically different approaches with identical conceptual breadth.