George Berkeley (bark-lee, or ber-ke-lee) (March 12, 1685–January 14, 1753), also known as Bishop Berkeley, was an influential Irish philosopher whose primary philosophical achievement is the advancement of what has come to be called subjective idealism, summed up in his dictum, "Esse est percipi" ("To be is to be perceived"). He wrote a number of works, the most widely-read of which are his Treatise Concerning the Principles of Human Knowledge (1710) and Three Dialogues between Hylas and Philonous (1713) (Philonous, the "lover of the mind", representing Berkeley himself). In 1734 he published The Analyst, a critique of the foundations of science, which was very influential in the subsequent development of mathematics.
George Berkeley was born in Dysert Castle, near Thomastown, Ireland. He attended Trinity College, Dublin completing a masters degree in 1707. He remained at Trinity College after completion of his degree as a tutor and Greek lecturer. In the period between 1714 and 1720 he interspersed his academic endeavours with periods of extensive travel in Europe. In 1721 he took holy orders, earning his doctorate in divinity, and once again chose to remain at Trinity College Dublin lecturing this time in Divinity and in Hebrew. In 1728 he sailed for the Americas with the goal of establishing a college and utopian community in Bermuda. He landed near Newport Rhode Island where he bought a farm to live on while he waited for funds for his college to arrive. However the funds were not forthcoming and in 1732 he returned to London. In 1734 he was appointed Bishop of Cloyne where he remained until 1752, when he retired and went to Oxford to live with his son.
UC Berkeley is named after him, and so, indirectly, is the city that developed around it. The pronunciation of his name has however evolved to suit American tastes.
Contributions to Philosophy
Though born in Ireland, Berkeley was very much an American philosopher. While it was in Ireland that Berkeley had his initial insights into the ideality of the objects of perception, his greatest philosophic insights and the most important projects of his life aimed at applying his principles (including his project to found a utopian society in Bermuda and his medical enterprises) began only with his trip to America.
As a young man, Berkeley theorised that the objects we perceive exist precisely as they appear to the senses. Objective knowledge is possible because the perceived object is the only object that exists. There is no "real" object which is the substratum of the perceived object. There is no "real" object (no matter) "behind" the object as we perceive it, which "causes" our perceptions. All that exists is the object as we perceive it, and this is the real object.
Since the object we perceive is the only object that exists, the object is precisely as it appears and, if we need to speak at all of the "real" or "material" object (the latter in particular being a confused term which Berkeley sought to dispose of), it is this perceived object to which all such names should exclusively refer.
This arouses the question whether this perceived object is "objective" in the sense of being "the same" for our fellow humans, in fact if even the concept of other human beings (beyond our perception of them) is valid. Berkeley argues that since we experience other humans in the way they speak to us—something which is not originating from any activity of our own—and since we learn that their view of the world is consistent with ours, we can believe in their existence and in the world being identical (similar) for everyone.
It follows that:
Our perceptions of objects are all perfectly accurate and objective.
Any knowledge of the empirical world is to be obtained only through direct perception.
Error comes about through thinking about what we perceive.
Knowledge of the empirical world of people and things and actions around us may be purified and perfected merely by stripping away all thought (and with it language) from our pure perceptions.
From this it follows that:
The ideal form of scientific knowledge is to be obtained by pursuing pure de-intellectualized perceptions.
If we would pursue these, we would be able to obtain the deepest insights into the natural world and the world of human thought and action which is available to man.
The goal of all science, therefore, is to de-intellectualize or de-conceptualize, and thereby purify, our perceptions.
Theologically, one consequence of Berkeley's views is that they require God to be present as an immediate cause of all our experiences. God is not the distant engineer of Newtonian machinery that in the fullness of time led to the growth of a tree in the university's quadrangle. Rather, my perception of the tree is an idea that God's mind has produced in mine, and the tree continue to exist in the Quad when "nobody" is there simply because God is always there.
The philosophy of David Hume concerning causality and objectivity is an elaboration of another aspect of Berkeley's philosophy. Immanuel Kant mischaracterized Berkeley as a radical idealist and falsely claimed that Berkeley's principles make objective knowledge impossible. As Berkeley's thought progressed, he more or less completely assimilated his theories to those of Plato. The only modern philosophers who adequately appreciated and applied Berkeley's principles were Hume and Arthur Schopenhauer.
The Analyst Controversy
In addition to his contributions to philosophy, Bishop Berkeley was also very influential in the development of mathematics, although in a rather negative sense. In 1734 he published The Analyst, subtitled A DISCOURSE Addressed to an Infidel Mathematician. The infidel mathematician in question is believed to have been either Edmond Halley, or Sir Isaac Newton himself, although the discourse would then have been posthumously addressed as Newton died in 1727. The Analyst represented a direct attack on the foundations and principles of calculus, and in particular the notion of fluxion or infinitesimal change which Newton and Leibniz had used to develop the calculus.
Berkeley regarded his criticism of calculus as part of his broader campaign against the religious implications of Newtonian mechanics -- as a defense of traditional Christianity against deism, which tends to distance God from His worshippers.
As a consequence of the resulting controversy, the foundations of calculus were rewritten in a much more formal and rigorous form using limits. It was not until 1966, with the publication of Abraham Robinson's book Non-standard Analysis, that the concept of the infinitesimal was made rigorous, thus giving an alternative way of overcoming the difficulties which Berkeley discovered in Newton's original approach.