It can be argued that the Forms don’t teach us anything about the physical world because Plato said that the Realm of the Forms is a world which no human has ever been to or can get to; they can only strive to be as close as they can to the Realm of the Forms, therefore humans cannot be taught anything about the real world from a Realm which doesn’t physically exist.
Furthermore, contained within the Realm of the Forms is the perfect version or copy of everything in the world, and everything in the world is just a copy of the perfect version in the Realm of the Forms, hence the Realm cannot teach us about any physical objects in the world if the object in the Realm is different to all the others on Earth. For example, in the Realm of the Forms will be the perfect version of a chair so, according to Plato, all the chairs in the physical world are copies of the perfect version so the perfect chair cannot teach us anything about a physical chair in the world that we know.
The physical world moves in time and space, so it is transitory, whereas the Realm of the Forms is outside time and space, so it is transcendental. This means that everything in the world is changing all the time as the years go by but the Forms never change. Therefore, the Forms may not be relevant to the world that we know today, only to the world of the time in which it was created. Consequently our world may be edging further and further away from the Forms all the time, due to the world in which we live constantly developing and changing.
The Realm of the Forms is beyond the senses so what is in the Realm does not rely on the senses, it is absolute, whereas everything in the physical world is determined and identified by our senses but people could argue that if we can see or touch something then it is physical and part of our world whereas if the Forms is beyond the senses then it is not physical because you cannot physically hear, touch, taste, smell or see what is in it.
Some may disagree and say that actually, if, in the Realm of the Forms, there is a perfect copy of everything, then people in the physical world will be able to identify an object and aim for perfection, and they know what perfection is because of the Realm of the Forms. In other words, the Forms do teach us something about the physical world – what is perfect.
