Grinker begins with a reminder about the importance of clear definitions for psychiatric disturbances and of unification of the language used by psychiatrists. It seems his plea is almost directly opposite to that of Giovacchini in the preceding chapter. Grinker goes on to give his own careful diagnostic classification of the borderline syndrome and its subtypes, based on studies of certain behavioral parameters. He agrees with Kernberg and Giovacchini in viewing the borderline syndrome as a specific state of "stable instability" characterized by "arrested development of ego functions."