Java takes its most basic ideas about how OOP is done from the Simula and C++ side, rather from Smalltalk and Objective-C. In that world view you don't ask if s

Java takes its most basic ideas about how OOP is done from the Simula and C++ side, rather from Smalltalk and Objective-C. In that world view you don't ask if something responds to a selector but rather whether it's an instance of a suitable interface. There are still occasions when responsa to/perform is a nice pattern but its often better done with lambdas. Perform also tends to need annoying special casing to optimise. The exception I'd make to that is meta-programming—especially for ORM libraries—where responds to, perform, and lambdas together produce some lovely patterns to marry a schematic to a dynamically generated object hierarchy.