ELI5: Explain Like I'm 5

Theory of forms

The theory of forms is an idea from the ancient Greek philosopher Plato. He believed that there are perfect, unchanging ideas that exist in a higher realm. Plato said that these perfect forms are the real versions of things like chairs, cats, love, beauty and justice. He believed that when we see, hear, touch and experience things in the physical world, we are actually only experiencing imperfect copies of these perfect forms.