Plato was also a dualist. This means he believed that the body and soul exist separately. The body is temporary and the soul has always existed. Our innate knowledge comes from when our soul pre-existed in the World of Forms before it entered the body. We remember the concepts of things which is why we can recognise that for example, a dog has 4 legs and a tail.
Plato’s dualistic views led him to come up with his idea of two different realms. The World of Forms or the Realm of Reality is perfect, unchanging and does not decay, it is where we can learn true knowledge. Whereas the Material World or World of Appearances is in a constant state of flux and so our empirical knowledge is just a set of objective, changing opinions.
Plato used the Form of Beauty to explain his forms. He said that we all have an idea of what beauty is because we have innate knowledge of the Form of Beauty. He also said that for example, when we refer to a dog we are actually referring to a quality, characteristic or essence that it has. In the World of Forms there is an ideal dog that is unchanging which we are seeing a mere, imperfect reflection of. That is why dogs we see in our world eventually grow old and die.
Plato believed that there is a hierarchy of Forms. For Plato, the most important Form is the Form of the Good. There is an aspect of good in all forms, e.g. beauty has goodness. Plato said that knowledge of the Form of the Good is an ‘end in itself’ and gives meaning and purpose to life.
To conclude, Plato was a dualist who believed that 2 realms exist. The world of Forms in which our souls pre-existed and where we gain true innate knowledge from. And the World of Appearances where our empirical knowledge is objective and changing and so cannot be trusted. There is a perfect form of everything that we can only see mere reflections of in our material world and the highest form- Form of the Good, exists in everything.