Lastly, John Locke stated that we define objects by primary and secondary properties; primary properties being undeniably objective features such as size and shape, and secondary properties being subjective such as colour and taste. Locke’s theory on reality is called Representative Realism, it is the view that sense data (an immediate object of perception, which is not a material object; a sense impression) somehow represents the objects and that these objects are causally involved in our production of the sense data. Our perception of objects is thus indirect; hence, representative realism is a kind of indirect realism. (An Introduction to Epistemology, second edition, 277) This view argues that we experience reality indirectly by perceptions that represent the real world. So, if we see a brown table, what we are actually seeing is not the table itself but a representation of it. In this way, differences of perception which occur due to changes in light conditions, position of viewer, etc., can be easily explained: it is not the object which is changing, only the perception of it. As an example, a man is standing on the corner of a busy road and witnesses two cars collide. Neither driver is hurt, but both step out of their cars to inspect the damage. Driver A is a young mother with a young child in the back of the car; driver B is a business executive in a hurry; the witness is an old man wearing glasses. As the two drivers argue about whose fault it was, the man approaches them and offers to confirm what he saw happening. What does each of them see? Whose is the correct view?