George Berkeley was an Irish philosopher. His philosophical beliefs were centered on one main belief, the belief that perception is the basis for existence. In doing so, he rejected the notion of a material world in favor of an immaterial world. Berkeley felt that all we really know about an object we learn from our perception of that object. He recognized that in the materialist’s view the real object is independent of any perceiver’s perception.
The pen on my desk would exist, whether or not I was in the room to see it or have a sensory experience of it in some way. Berkeley rejected this idea. He realized that knowledge is limited to perception. In this realization, he postulated that everything we know we learned through some sort of sensory perception. He demonstrated that there was a veil of ignorance separating the materialist’s real object and the perceived object.
For instance, if one could not ever perceive the pen, how could one ever know of its existence? He held that if an object is independent of one’s perception, then how could one know it to be real. He thought that you could not truly know something without first perceiving it in some way. It was an easy step from that ideology for him to adopt the phrase – Esse Est Perc ipi, which means, “To be is to be perceived.” There is a crippling problem that arises in this mode of thinking that can best be demonstrated by the following limerick: There once was a young man, who said “God, must find it extremely odd to think that this tree will continue to be when there is no one about in the quad.” Dear Sir, I’m always about in the quad and that’s why this tree will continue to be since observed by Yours Faithfully, God This limerick demonstrates the devastating problem with this mode of thought and also a possible solution. What, then, happens to an object when no one can perceive it anymore? If no one sees the tree and no one has a sensory experience of it, does it cease to exist? This idea suggests that objects pop in and out of reality when not being perceived by any human perceiver. Berkeley argues from an im materialist standpoint and says that objects do not act in such a manner. He tries to save his theory by saying that the tree does in fact exist because God is the continuous perceiver of all things and therefore God always perceives the tree.
... God can perceive this things, why does he not bless us alike all the other ideas and perception of bodies. In fact, Berkeleys ... they are perceived, physical objects are collection of ideas, therefore, physical objects only exist when perceive. If this proposal holds, Berkeley is force ... does not show that you can conceive it possible. The objects of your thought may exist without your mind. To ...
This is an illegitimate appeal to save his philosophy. By saving his theory in this manner he “shoots himself in the foot.” If God cannot be perceived, and if to be is to be perceived, then God cannot possibly exist. Although the existence of God can be inferred through the classical ontological argument, doing so scuttles his immaterial world. If one can have knowledge through inference, then one can infer the existence of a material world. Berkeley’s answer to the existence of the tree in the quad is not convincing because his argument is circular. If something must be perceived in order for it to exist and if no one is around to perceive that something, then God, being the continuous perceiver of all things, must be perceiving it.
Yet, if God is himself not an object of perception, then according to Berkeley’s ideas, God can not exist, and neither can Berkeley’s argument.