Economic theory, of necessity, presents an abstraction to the reader. Abstraction is required to achieve the perspective that allows for theory, that is to say, understanding and interpretation, to occur. If the abstraction is done well only inessential details are set aside -- details that would otherwise divert the theorist from grasping the essential or fundamental elements of the process under examination. For example a study of the mechanisms that cause a moving automobile to stop can reasonably abstract from the vehicle's color scheme.