George Berkeley

"Some truths there are, so near and obvious to the mind,
that a man need only open his eyes to see them."George Berkeley

George Berkeley was an Irish philosopher who put forth the theory of subjective idealism. It is most famously expressed in his dictum, "Esse est percipi" or "To be is to be perceived". Berkeley believed that people could only know the sensations and ideas of things. Concepts like "matter" and “object” had no reality outside of the mind. His most widely-read work is A Treatise Concerning the Principles of Human Knowledge which was written in 1710.

Upon the whole, I am inclined to think that the far greater part, if not all, of those difficulties which have hitherto amused philosophers, and blocked up the way to knowledge, are entirely owing to ourselves - that we have first raised a dust and then complain we cannot see.

Both the University of California and the city “Berkeley” are named after this great Irish philosopher. His theories are considered to be an example of empiricism at its most extreme form as he explains that there aren’t any "real objects” in the world at all. Perception is all there is. Perception is not “caused” by an objective world because everything is merely an idea in the mind.

Skeptics of Berkeley’s theory often attack it from various angles and Dr. Samuel Johnson is famously noted for having kicked a heavy stone and exclaimed, "I refute it thus!" Other skeptics also ask the question “What makes an object continue to exist after we stop perceiving it?” The answer given by Berkeley to his skeptics is that God is the Ultimate Perceiver who constantly keeps watch over all things even when we are not around to see them. This argument between Berkeley his skeptics was famously illustrated in a limerick by the theologian Ronald Knox.

There was a young man who said ‘God Must find it exceedingly odd To think that the tree Should continue to be When there's no one about in the quad.’

‘Dear Sir: Your astonishment's odd; I am always about in the quad. And that's why the tree Will continue to be Since observed by, Yours faithfully, God.’

In addition to his ideas about the essential nature of God and perception, Berkeley insisted that philosophers undergo a process wherein knowledge of the world become more purified. This would be done by stripping thought from the delusion of language and arriving at a more pure and direct perception of the world.

Unless we take care to clear the first principles of knowledge from the… delusion of words, we may make infinite reasonings upon them to no purpose; we may draw consequences from consequences, and be never the wiser…Whoever therefore designs to read the following sheets, I entreat him to make my words the occasion of his own thinking,… By this means it will be easy for him to discover the truth or falsity of what I say.

German philosopher Arthur Schopenhauer made a notable reference when he said "Berkeley was, therefore, the first to treat the subjective starting-point really seriously and to demonstrate irrefutably its absolute necessity. He is the father of Idealism."

References

Berkeley, George