What is 'objective' value?

[Kingpin]

Plato was one of the first philosophers to argue for objective value (in direct opposition to the radical relativist Protagoras).  Plato developed a dual level conception of reality.  He argued that we humans are limited in time and space, our perception and intellect are subject to error, our point of view limits what we can apprehend and understand.  Still, even though it is out of our understanding, we can form concepts of the infinite, whole, eternal, true universe.  In his book, Republic, Plato made a powerful image to explain this.  One is the Divided Line:



So in red, above the line, are the attributes of objective reality, below are the attributes of relative reality.