Plato believed that the senses could not lead to knowledge and only through our reason could we gain true knowledge of them. The objects we see within the physical world are just imitations of their ideal Form. However, Plato’s argument against the use of our senses seems potentially ridiculous. As the human race has thrived since the days of cave men, it seems unruly to say that our senses are unreliable and cannot lead to knowledge since our race has used senses to survive for millenniums and centuries. Therefore the Forms cannot teach us anything about the physical world as they contradict the way the human race has survived by suggesting that only reason can lead to knowledge.
The Form of the Good is seen as ‘the Form of the Forms’ in the eyes of Plato as it illuminates all of the other Forms and gives them their value. It was represented by the sun in Plato’s Allegory of the Cave as the sun gives life to all other Forms, such as the idea that growth cannot occur without the sun, nor can anyone see without the light of the sun. However, Aristotle suggested that Good comes in many different varieties that there cannot be only one Form of it. For example, the goodness of a person differs from the Goodness of a chair. It is also argued that what is Good is ‘culturally relative’. This shows how the Forms teach us nothing about the physical world as concepts such as good differ between situations and cultures so cannot be used for all circumstances in the physical world.
Plato insists that everything that exists in the World of Appearances is merely a pale reflection of its true form in the World of the Forms. He is unclear of what exists there and leaves open the question of whether negativity exists in the WOF. Therefore this could be that the WOF contains negative forms such as the Form of Cancer, Violence, Death or even evil. If we accept that the physical realm is a poor reflection of the WOF, then these negative concepts would be ‘perfect’ in their negativity. The Forms therefore teach nothing of the Physical World as the WOF could be more negative and distressed than the physical world if negative Forms exist.
However, it can be argued that the Forms do in fact teach us something about the physical world. The theory of the Forms encourages us to question our senses and not rely on accepted truths. It helps to reveal the sometimes unreliable side to our senses when they deceive us and helps us to use our reason more than we previously would have. The theory of the Forms also helps us to recognise why we can distinguish certain concepts in the physical world such as justice and beauty. It provides an explanation for our understanding of concepts and helps to teach us about our soul identifying them in the physical world.
In conclusion, the Forms teach us to use our reason more in society and to test our senses, however it mostly does not teach us anything about the physical world as the Forms themselves cannot be proved and are only a theory by an Ancient Greek philosopher so therefore they cannot teach anything about our world without proof of their own existence.