Hi I was reading the code of TBehavior and I'm puzzled. I do not get why - initialize does not call superclass: aClass methodDictionary: mDict format: fmt - what is this comment about not sending messages.... and doing it just after :( TBehavior >> initialize "moved here from the class side's #new" super initialize. self superclass: Object. "no longer sending any messages, some of them crash the VM" self methodDict: self emptyMethodDictionary. self setFormat: Object format. self traitComposition: nil. self users: IdentitySet new. TBehavior >> superclass: aClass methodDictionary: mDict format: fmt "Basic initialization of the receiver. Must only be sent to a new instance; else we would need Object flushCache." self superclass: aClass. self setFormat: fmt. self methodDict: mDict. self traitComposition: nil I really think that I would like to revisit the traits introduction in the kernel. Stef