Plato

In Plato’s philosophy (427-347 BC) the world is conceived as if it had two floors: on the lower level there is the world of particular objects, with all their limitations and imperfections; on the upper one there is the world of ideas, containing, as its name says, abstract, general, perfect ideas. For example, a horse we see in the countryside is full of particular aspects that constitute its exclusive appearance, making it different from all other horses in the world. For this reason we do not say that that is “the horse”, but that it is “a horse”. “The horse”, meant in a general sense, exists, according to Plato, in the world of ideas; “this horse” that we have in front of us is just a rough copy of the ideal horse. According to this way of thinking, truth lies in the world of ideas: perfection, the true reality of things, lies there. Instead, in the world that falls before our eyes we find individual things to which we give a name to the extent that they correspond to an abstract and perfect idea of the world of ideas.
Today almost all of our ways of thinking are vstill set according to this scheme. The words we use are an essential element of this structure. We distinguish in words a “signifier” and a “signified” (based on the theory of signs by Ferdinand de Saussure, 1857-1913). The “signifier” is made up of the material component of the word: it can be the sound we make in pronouncing it or the marks we draw on paper when we write it; the “signified” is instead what one thinks by looking at those signs on the paper or by listening to those sounds. It is easy to recognize in this distinction a Platonic correspondence between the material world (the signifier) and the world of ideas (the signified). The same thing can be recognized when we speak of symbols, signs and interpretations, or of a speech and its content; sometimes we say that “that speech was poor in content”. Another context of ideas that we can refer to Plato is the distinction between body and soul; the body, considered a rough copy of the most authentic essence, constituted by the soul, refers to the two worlds of Plato. The same could be said about the earthly world and the supernatural world or “the afterlife”.
These distinctions are undoubtedly open to criticism and in what follows we will try to better understand better why; here we are just going to keep it in mind and foresee that we cannot have too much faith in the distinction of “concept”, “signified”, “meaning”, “soul”, “spirit”, “truth”, “idea”. This criticism is connected to the criticism of the abstractions that we have considered about Parmenides. Today the problem is studied in depth by two important disciplines: “semantics” and “semiotics” (respectively “study of signified” and “study of signifiers”) and we could even say by physics and medicine, if we consider that the “meaning” can be understood as a set of neurons that are activated in our brain. The critical awareness about all of this helps us to move better among of all other issues; we are not going to reject useful distinctions, we just want to keep awareness of their being open to criticism and of the problems they carry with them.
Two more interesting elements of Plato’s thought are the myth of the cave and that of the charioteer. In the first one people are like prisoners inside a cave, they see in it the shadows cast from outside and think that those shadows are reality; the philosopher leaves the cave, sees reality, wants to make it known by the prisoners and free them, but they refuse because, they are bothered by too much light and they believe that the philosopher is a fool. In the myth of the charioteer each of us is like one who drives a chariot with two horses, one white and one black; the driver represents reason, the philosopher; the white horse is obedient and represents the highest spiritual passions typical of the warrior: honor, friendship, courage; the black one is recalcitrant and represents the lowest and most material instincts, typical of farmers and artisans: eating, pleasures. According to Plato the charioteer has to commit himself to driving trying to keep these two forces in harmony.