When solving a particular problem in an OO language, it often makes sense to take a step back and think about the conceptual entities...

When solving a particular problem in an OO language, it often makes sense to take a step back and think about the conceptual entities involved and how they collaborate with one another. By adhering to some basic design principles, notably the separation of concerns and encapsulation, we have a solution

When solving a particular problem in an OO language, it often makes sense to take a step back and think about the conceptual entities involved and how they collaborate with one another. By adhering to some basic design principles, notably the separation of concerns and encapsulation, we have a solution that is easier to understand and maintain.

Patrick Reagan,  Using Object-Oriented Programming to Manage Control Flow in Rails Controllers