This is about John Locke's argument on how we gain perceptual knowledge of external bodies.

It is said that one learns something new each day. At a young age one learns the basics of mathematics, speaking, writing etc. Nevertheless, how does one learn what a tree is, what it looks like, the color, smell, shape? One might learn that a tree is part of the Spermatophyte division, or that I its leaves are green and contain chlorophyll and even that paper can be made from it, but how does one …

…support his argument of perceptual knowledge with excellent examples, I ultimately feel that with all the problems he does not have a good account of perceptual knowledge. Locke's arguments developed an empiricist account of science and knowledge. His belief that ideas are the foundation for all perceptual knowledge is still today in question. His classification of ideas and argument on the non existence of secondary qualities has become important in the world of modern philosophy.