Platonic idealism usually refers to Plato's theory of forms or doctrine of ideas. Platonic idealism usually refers to Plato's theory of forms or doctrine of ideas. Some commentators hold that Plato argued that truth is an abstraction. In other words, we are urged to believe that Plato's theory of ideals is an abstraction, divorced from the so-called external world, of modern European philosophy, despite the fact Plato taught that ideals are ultimately real, and different from non-ideal things—indeed, he argued for a distinction between the ideal and non-ideal realm. These commentators speak thus: for example, a particular tree, with a branch or two missing, possibly alive, possibly dead, and with the initials of two lovers carved into its bark, is distinct from the abstract form of Tree-ness. A Tree is the ideal that each of us holds that allows us to identify the imperfect reflections of trees all around us. Plato gives the divided line as an outline of this theory. At the top of the line, the Form of the Goodis found, directing everything underneath. Some contemporary linguistic philosophers construe 'Platonism' to mean the proposition that universals exist independently of particulars (a universal is anything that can be predicated of a particular). Platonism is an ancient school of philosophy, founded by Plato; at the beginning, this school had a physical existence at a site just outside the walls of Athens called the Academy, as well as the intellectual unity of a shared approach to philosophizing.