If we are directly aware of ideas in our minds and not of the external world, then our naive realist understanding of perception cannot be maintained.
So Locke, who typified the new philosophers, abandoned Naive Realism in favour of Representative Realism.
In this essay I shall give the historical background to Berkeley's Idealism and then offer an argument for Idealism and suggest how an idealist could defend his theory against common objections and criticisms.
Bishop George Berkeley's Idealism or Immaterialism is the theory that the physical world exists only in the experiences minds have of it.
One of the important things we must be clear about when taking about Idealism is the term 'idea' itself.
As used by Berkeley and Locke the term 'idea' does not have its normal sense.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.Further, not only are these worlds different qualitatively, but they are located in different realms.If we accept that the things of which we are immediately aware possess secondary qualities and that these secondary qualities exist only 'in the mind', then what we are aware of are, 'ideas in the mind', not objects in the external world.Descartes, in an attempt to highlight the possibility that there may be no external world, suggested that our experience might be the product of an evil demon whose intent was to deceive us.In an attempt to refute such sceptical possibilities Descartes tried to prove, a priori, the existence of a good God.The combination of Atomism and Newton's mechanistic and thus deterministic view of the world created major difficulties in understanding how it was possible for immaterial spirits such as God or the soul, to be related to the physical world.The principal difficulty was in understanding how a material and immaterial substance could causally interact.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.