chapter presents, as stated in the full title, A Model of Mental Fluidity and Analogy-making. It is a description of the architecture of the Copycat program, developed by Hofstadter and Melanie Mitchell. The field of application of the program is a domain of short alphabetic sequences. A typical puzzle is: If abc were changed to abd, how would you change ijk in the same way?. The program tries to find an answer using a strategy supposedly similar to the way the human mind tackles the question. Copycat has three major components: The Slipnet, a model of long-term memory in humans. It contains concepts of various degrees of abstraction, from the letter types to the notion of opposite. Concepts are connected with links indicating their similarity. The activation of a node may cause the activation of a neighbor with a probability proportional to the inverse of the length of their link. The lengths of these links are not static; they have a value at the beginning but they may change elastically during computation according to the partial results achieved. The Workspace, a model of short-term memory. Here partial structures are constructed and dismantled. The temporary results may cause the activation of concepts in the slipnet. A temperature measures the satisfaction of the program with the structure obtained at each moment. High temperature means dissatisfaction and leads to the adoption of a different strategy. Low temperature means satisfaction and the continuation of the present strategy. The Coderack, a collection of codelets, that is small fragments of code, that wait to be selected and executed in the workspace. Each has a weight associated to it that determined its probability to be selected for execution. The resulting software displays emergent properties. It works according to a parallel terraced scan that runs several possible processes at the same time. It shows mental fluidity in that concepts may slip into similar ones. It emulates human behavior in tending to find the most obvious solutions most of the time but being more satisfied (as witnessed by low temperature) by more clever and deep answers that it finds more rarely. Chapter 6: Perspectives on Copycat This chapter compares Copycat with other recent (at the time) work in artificial intelligence. Specifically, it matches it with the claimed results from the structure mapping engine SME and the Analogical Constraint Mapping Engine (ACME). The authors' judgment is that those programs suffer