At the time that Plato lived (century. IV a. C.), the conception that man knows through his senses was very common. However, for many sages of the time, knowledge not only began but could not go beyond sensitivity. The Protagorian maxim is remarkable in this period: “man is the measure of all things”. This is equivalent to saying that each being is only enclosed in their subjective representations that or was impossible an absolute truth (but a particular one, of each one) or that it was impossible any knowledge.
This way of thinking comes from the philosophy of Heraclitus for whom everything is in motion. Now, Plato asks himself, if everything is in motion, at the very moment that something is determined, it has already changed, has already been transformed and, with that, knowledge becomes impossible! Likewise, if there are only subjective, particular or relative truths, the Idea of truth itself does not exist at all, which also makes error, therefore, knowledge impossible.
To overcome this notion of transitory reality, Plato needs to show how our senses are capable of deceiving us and that, for this reason, we must look elsewhere for the foundation of knowing. This “place” is the soul.
Plato thinks that it is intelligence that guarantees the stability of sentient beings. This means that the transience evidenced in sensible things cannot give reason for themselves and for themselves. Hence, it is necessary to try to understand that all knowledge comes from the reasoning that achieves the form of objects, a form that keeps within itself a timeless and indestructible identity.
Man must, therefore, seek to ascend from the sensible world to the intelligible in order to have a real knowledge of beings. It must, first of all, abandon its preconceptions, its prejudgments, its points of view distorted by unreflective opinions and, from that, start the scale towards the Ideas.
Idea, according to Plato, is an intelligible principle, which does not suffer generation or corruption, being, therefore, the foundation of knowledge of things. However, man can only reach ideas by his reason, by reflective thinking that, when abstracting all the physical particularities of the objects studied, manages to intuit the determining form of each being, giving it stability and allowing to be known. Ideas are purely spiritual, containing no materiality or contact with the sensible world. In fact, this has its way of being, of existing only by participating in the ideas of the intelligible world. The intelligible transcends the sensible and determines it.
In this way, we are already born with the intelligible principles that would allow us to know the sensible world. It is up to man not to let himself be fascinated by sensations, but to subordinate them to intelligence in order to really know the truth of beings and of himself, dedicating his life to the formation of the spirit.
By João Francisco P. Cabral
Brazil School Collaborator
Graduated in Philosophy from the Federal University of Uberlândia - UFU
Master's student in Philosophy at the State University of Campinas - UNICAMP
Source: Brazil School - https://brasilescola.uol.com.br/filosofia/epistemologia-ou-teoria-conhecimento-platao.htm
