When a program crashes, you need access to information. You might want to know which method Smalltalk was evaluating when the crash occurred, or the class in which that method is defined, or the sequence of messages that led up to the evaluation of that method, or the values of various parameters and variables in that method; or you might want to start over and step slowly through program evaluation. Smalltalk's debugging system readily delivers all such information to you, making that debugging system one of the special strengths of the language.