George Berkeley was born near Kilkenny, Ireland, and, although an Anglican of English descent, he emphatically considered himself to be Irish. He studied at Kilkenny College and in 1700 went on to Trinity College, Dublin. There he read Descartes, Newton, and Hobbes. In 1707, he became a Fellow of the College and was ordained in the Anglican church. The next six years were to be the most philosophically productive in his life. In 1709, he published his New Theory of Vision, and in the following year his most important philosophic work, A Treatise Concerning the Principles of Human Knowledge. In 1711, he wrote Discourse on Passive Obedience. Two years later, he published a more popular exposition of the doctrine of his Principles in the form of Three Dialogues Between Hylas and Philonous.
For the next eleven years, Berkeley traveled widely, visiting with many of the great thinkers of his day. He became Dean of Derry in 1724, though most of his energy at this time seems to have been given to the founding of a college in the Bermudas. With promises of financial support, he sailed for Rhode Island in 1728 to establish farms for supplying his future college with food. Berkeley spent two and a half years in Rhode Island with his new wife and friends, waiting for the £20,000 the government had promised. When the funds never arrived, he finally gave up and returned to London.
In 1733, he published Alciphron, or The Minute Philosopher, against the freethinkers (agnostics), and in the following year The Analyst, a criticism of Newton. That same year, he was made Bishop of Cloyne. For the next eighteen years, he energetically served his remote, poor diocese. Among the works he wrote during this period are The Querist (1737), which used questions to propose public works and education as remedies to the crushing poverty he observed, and Siris (1744), an unusual work dealing with the medicinal value of tar water. In 1751, he lost his eldest son, and the next year he moved to Oxford, where another son was beginning his studies. On January 14, 1753, Berkeley died suddenly and he was buried at Christ Church, Oxford.Like Locke before him, Berkeley accepted the empiricist doctrine that all we can know are ideas and that ideas come from perception or reflection. But Berkeley saw a problem in Locke's assertion of an external world of material "substances" giving rise to perceptions. If all we can know are ideas, how can we know there is a world "out there" giving rise to our ideas? Locke had said that the primary qualities of an "external object" (such as extension and solidity) are "utterly inseparable" from the objects themselves, whereas this is not the case with secondary qualities (such as color, taste, etc.). But again, asked Berkeley, how can Locke know this? He cannot get "outside himself" to see which of his perceptions are actually a part of objects "out there." Berkeley concluded that Locke's philosophy will lead to skepticism, whereby we must admit that we cannot really know anything about the world "out there."
To avoid this skepticism, Berkeley made the radical claim that there is no "out there," or, more precisely, there is no matter. Berkeley's position, which is called "idealism," can be summed up in his famous phrase "esse is percipi": to be is to be perceived. What we call "bodies," or physical objects, are simply stable collections of perceptions to which we give names such as "apples," "trees," and so on. These collections of perceptions have no existence apart from a perceiving mind. The answer to the famous conundrum "If a tree falls in the forest and no one hears it, does it make a sound?" is that if no one is perceiving it, it not only does not make a sound, the tree does not even exist!
Does this mean that trees go out of existence when no one is left in the forest to perceive them and that they come back into existence when someone enters the forest to perceive them again? It would seem that Berkeley must accept this odd conclusion were it not for one important point: God never leaves the forest and God is always perceiving the trees. By always holding all collections of perceptions in the divine mind, God ensures their continued existence and the perceived regularity in what we call "nature." This point has been classically formulated in the following limericks:
There was a young man who said, "God,
Must think it exceedingly odd
If he finds that this tree
Continues to be
When there's no one about in the Quad."REPLY:
"Dear Sir: Your astonishment's odd:
I am always about in the Quad.
And that's why the tree
Continues to be,
Since observed by, Yours faithfully, God."
Berkeley saw his philosophy as a common-sense attack on the metaphysical excesses of medieval Scholastics, Continental Rationalists, and even fellow empiricists such as Hobbes and Locke. Although Berkeley understood his philosophy to be common sense, his readers came to different conclusions. One prominent physician of his day claimed Berkeley was insane. The great Dr. Samuel Johnson dismissed Berkeley's ideas with his famous "I refute Berkeley thus" and then he kicked a rock. Of course, this did not refute Berkeley at all. It only proved Johnson had not understood Berkeley's point. Berkeley did not claim the non-existence of stones or that kicking a stone will not produce sensation. He claimed the rock did not exist apart from the perception of its solidity or the perception of pain when struck, and so on. An oft-repeated epitaph summarizes the general reaction to Berkeley: "His arguments produce no conviction, though they cannot be refuted."
By Forrest Baird © 2000 by Prentice Hall from Philosophic Classics, Volume III