Plato’s Forms are universals, the abstract concepts or types behind all particular things. The Form of Beauty, for instance, is that which makes any particular thing beautiful; it is the essence of beauty. Plato introduced the concept of Forms to explain our perception of the world. He believed that there were eternal, perfect and unchanging Forms, which existed in a realm beyond our reality. These Forms are apprehended by the reason (nous), not by the senses. However, we can only have knowledge of them through our senses, so they must exist within some reality.
Philosopher’s theory of Forms provides him with a way of explaining how we can know about things we have never seen or touched. If there is a Form of Beauty and a Form of Goodness and so on for everything else in the world, then we can know what they look like because they exist in our minds. We can think about goodness or beauty without having to look at anything that is good or beautiful – because goodness and beauty themselves are abstractions drawn from our experiences with individual instances of goodness and beauty.
However, Plato’s theory has its problems: it seems to imply that if we had never been exposed to an object before (say, a unicorn), we could not conceive what one looked like even if it did exist somewhere out there in reality.
