He said most philosophers make an assumption that has no proof of the existence of matter. Berkley questioned the inference that material things cause our sensory experience or that our sensory experience is material things. Berkeley originally wondered if we as humans actually experience an object as it really was, or was what we physically saw. The materialist feels that the information received through sense experience gives a representative picture of the outside world and one cannot penetrate to the true essence of an object¦
Although the idea is logical, it does contain certain grounding for agnosticism. John Locke claimed that primary qualities are those that exist within the body of an object and outside of our perception. He believed they are inseparable from body and his list consisted of motion, bulk, figure, number, and texture. Primary qualities are those qualities, which are present in the object itself, such as extension. Secondary qualities are only present in the viewer, such as color.
In a world in which there are no animals with color vision, there are still objects that reflect lights of various wavelengths, but there is no being that would interpret those waves as color. He supported his definition of primary qualities by claiming that if an object were continuously divided, the primary qualities would remain the same. However, he suggested that secondary qualities were only powers that the object has to cause us to have ideas about its color, smell, taste, sound etc.
These secondary qualities depend on and thus can be altered by altering primary qualities, as they do not actually exist within the object, nor do they exist independently of our minds. Primary qualities are immediately visible in the object, while secondary qualities require our sensory system to respond to the primary qualities of an object first. Therefore Locke claims that primary qualities are objective; whereas, secondary qualities are contingent on perception Locke did not believe that there was anything innate in anyone and that all concepts, ideas, and thoughts were the result of sensory experience.
According to Locke, there is no such thing as innate knowledge. Berkeley also shows that the perceived qualities of an object are ideas that exist only in a mind since sensations are the same as ideas; humans can only have one idea at once. On the other hand, Gods mind is infinite and is thus able to have multiple perceptions. These perceptions of God are also ideas, and it follows that these ideas comprise the reality beheld in the finite human mind.
Instead of the materialists belief in the representative theory of perception, where a material object has real qualities which humans perceive as sensible qualities. Locke had retained a certain faith in the capacity of the human mind to grasp, however imperfectly, the general outlines of an external world by means of combining operations. With Berkeley, there had been no necessary material basis for experience, though the mind had retained a certain independent spiritual power derived from Gods mind, and the world experienced by the mind derived its order from the same source.
Berkeleys theory is that God upholds all of the ideas, which comprise human reality, and people perceive these ideas as sensations directly from Gods infinite mind. Berkeley also denied the existence of what are called abstract objects universals and forms or ideas. For instance, if someone said that redness exists apart from any red thing or that goodness exists apart from any good action or person, then he is saying that redness and goodness exist as independent entities.
For Berkeley this is impossible, since nothing that is not being perceived can exist. The idea of redness without a red thing or goodness without a good action is a nonsense idea, every bit as much as matter without a sensation of it. Locke is an empiricist while Berkeley is an idealist, but Lockes most significant idea is that the human mind begins as a blank slate (tabula rasa), which is written on thru the course of his or her experiences and education. He did raise important questions, and created a dialog that led to better theories.