Further, not only are these worlds different qualitatively, but they are located in different realms.
Atomists believed that bodies are made from minute particles.
Further, they believed that the particles and the bodies made from them, possess primary and not secondary properties.
Berkeley therefore, rather than abandon direct realism, chose to modify the principle of the mind-dependence of the physical world.
According to Berkeley, the mind independence of objects is not absolute, but relative.
The most important exception from this viewpoint was that of Descartes.
Although he rejected atomism, he did agree that bodies only really possess primary qualities.Therefore, although these ideas of which we are aware can be held to represent, and in terms of primary qualities, resemble, objects in the world, they also constitute a 'veil of perception' which stands between the perceiver and the external world.From this we can conclude that the external world, as investigated by science, is different from the experiential or phenomenal realm.Berkeley, however, was adamant that he held on to the notion that we are directly aware of the physical world itself, while at the same time accepting that what we are aware of must be mind-dependent ideas.He concluded that the physical world consists essentially of ideas in our minds — that is esse est percipi : for material objects, to be is to be perceived.Basically what this means is that bodies in themselves possess shape, size, motion and impenetrability but not colour, sound, taste, hardness or smell.This latter group of qualities are sense dependent e.g. The crucial point is that since these secondary qualities are a vital component of the way we experience the world, it naturally follows that the world of experience is quite different from the world as described by science.By adopting the term 'idea' for all mental objects Locke declared his intent to assimilate the intellectual and the sensory to each other, and to make the sensory the model for both.If we accept that we are directly aware of ideas in the mind and not of external things, it becomes pressing to prove that there are really any external things at all.Descartes argued that such a good God would not deceive us, nor allow us to be deceived, in something so fundamental as our belief in the external world.However, Descartes's proof of the existence of God was not generally accepted, even amongst theists.