George Berkeley was a an Irish bishop and eminent empiricist philosopher whose main philosophical achievement was the theory of empirical idealism or immaterialism, summarized by his aphorism esse est percipi (“to be is to be perceived”). Berkeley was born in 1685 in the Kilkenny county, Ireland. Although Berkeley’s father was English, George always considered himself Irish. Berkeley attended Kilkenny College for several years before going to Trinity College in Dublin in 1700. Berkeley completed his Masters degree in 1707 and became a Senior Fellow in 1717. Berkeley was ordained as an Anglican priest in 1710, which was common at the time for British academics. Berkeley remained at his alma mater until 1724 as both a tutor and a Greek lecturer.
For Berkeley the philosopher, things that do not have the ability to think, like ideas, are perceived and it is the mind (human or divine) that perceives them. Berkeley's theory shows that individuals can only know the sensations and ideas of objects, but not abstractions like matter or general entities. Berkeley’s central principle of his philosophy is that ideas do not exist outside of a mind perceiving them. This is also an intuitive kind of truth: when I say that an object exists, I mean that I can feel it, that I can see it, or that it is perceived by another mind. As a result, for Berkeley it is impossible to conceive of an absolute and independent reality; esse est percipi (“to be is to be perceived”). The “esse” or being of the object is in its “percipi” or being perceived. Therefore we can only speak of things to the extent that they are in direct relationship with our mind.
While at Trinity College, Berkeley also spent time away in London where he associated with important intellectuals such as the Irish poet and satirist Jonathan Swift (1667-1745), the English essayist and poet Joseph Addison (1672-1719), the Irish essayist and playwright Sir Richard Steele (1709-1729) and the English poet Alexander Pope (1688-1744). George Berkeley also visited Europe extensively as he accompanied both Lord Peterborough (1713-1714) and cleric St. George Ashe (1658-1718), son of the Trinity College Provost, on their continental tours.
George Berkeley made great contributions to the fields of philosophy, mathematics and economics. Along with John Locke (1632-1704) and David Hume (1711-1776), George Berkeley is one of the most famous Empiricists. Indeed, Berkeley advanced the theory of “immaterialism” and is widely considered one of the greatest philosophers of the early modern era. Berkeley’s most-studied works today are An Essay towards a New Theory of Vision (1709), A Treatise Concerning the Principles of Human Knowledge (1710) and Three Dialogues Between Hylas and Philonous (1713). Berkeley’s work has become increasingly popular since the middle of the 20th century. This is due in part to the fact that George Berkeley wrote on many modern issues such as perception, but also most importantly the subject of the importance of language.
George Berkeley was an immaterialist. He believed that objects were merely collections of ideas and rejected the notion that material things were mind-independent or substances (here the term “materialism” is used to mean “the doctrine that material things exist”). Berkeley argued that when we perceive ordinary objects (a house for example), we perceive only ideas (the idea of house as opposed to the thing house). Therefore ordinary objects are ideas. To him the world was made up of nothing but minds and ideas. For example in his discourse on vision he explains how ones’ vision is learned by the perception of touch which then allows one to judge distance, magnitude and so forth. The ideas of one sense evolve into the signs of ideas of other senses. For Berkeley, this is how we construct our understanding of the world, and its application is far-reaching. Based on this argument scientific constructs are thus disregarded. Newtonian time and space vanish and time becomes the progression of ideas in individual minds. Mathematics is simplified to a system of signs in which words and numerals signify simply words and numerals, and science is a system of natural signs.
In his 1709 essay on vision, An Essay towards a New Theory of Vision, Berkeley made a significant contribution to the psychology of vision. This work was meant to demonstrate the manner in which thanks to sight we perceive distance, magnitude, and the situation of objects. In Principles of Human Knowledge Berkeley attacks abstractions. According to John Locke, the doctrine of abstraction elucidates how knowledge can first be communicated and then built upon. Berkeley dismisses the belief in the necessity of abstract thought for communication. Berkeley also disagrees that abstract thought leads to a more complex and advanced development in thought. Berkeley refuted the plausibility of abstraction by arguing that he himself could not imagine some of the examples used by Locke. For example, an abstract general triangle.
George Berkeley wrote his most well known works while at Trinity College. Berkeley began philosophical notebooks, traditionally referred to as Philosophical Commentaries (1707-1808). They were written in a fairly personal way for they were never intended for publication. Through doing the critique of René Descartes (1596-1650), Locke, Nicolas Malebranche (1638-1715), Isaac Newton (1642-1727), Thomas Hobbes (1588-1679) and other important thinkers, these “commentaries” document the early philosophical development of Berkeley’s immaterialism and idealism. We must note, however, Berkeley's idealism should not be confused with that of Immanuel Kant (1724-1804) or that of G.W.F. Hegel (1770-1831), which are radically different. Berkeley was against transcendental idealism. Kant qualified his own idealism as being “transcendental” as opposed to what he termed the “problematic” idealism of Descartes and the “dogmatic” one of Berkeley. Much later, Edmund Husserl (1859-1938) also called his idealism “transcendental”, albeit in a sense similar but not identical to that of Kant. Transcendental idealism means that there exists beyond the phenomena (or representations) a priori forms which determine phenomena without being themselves phenomena. These forms are, for Kant, space and time. For I still see phenomena in space, but I do not see space itself, and similarly with time.
For Kant et al., transcendentalism adds to these a priori forms, a priori categories of understanding (quality, quantity, relation, modality) as well as a “transcendental” subject that accompanies all representations. For Berkeley, however, as for empiricists in general, there are no a priori entities; everything is empirical and a posteriori. Kant coined the word “transcendental” precisely to refute “empirical” idealism. As for the “problematic” idealism of Descartes, the point was to question the reality of external existence but to keep as absolute the reality of the thinking subject (the cogito). Empiricists, and thus Berkeley, on the other hand, even doubt the reality of the subject as a permanent thinking substance. There is not, according to them, any cogito or transcendental subject.
George Berkeley is also against speculative idealism. Hegel argued for an idealism that is “speculative”, as opposed to “transcendental”. For according to Hegel the transcendental always indicates a finite and conditioned reason, while speculative reason indicates one that always goes beyond itself and thus becomes infinite and unconditioned. Such idealism, however, has nothing to do with the idealism of Berkeley because Hegel makes of reason an absolute that self-generates itself by facing being. For George Berkeley reason has no sort of reality; it is simply a convenient instrument to express empirical experience.
Plato (c. 429-c. 347 bc) saw things in a related, though ultimately far from identical way. Plato is said to be an “idealist” because for him there is only reality in ideas, and not for things, which according to him are only imperfect copies of the models of the ideas. For Berkeley, it is exactly the opposite: abstract ideas do not exist, there are only specific ideas, which are perceived objects. Berkeley will even challenge the Aristotelian and Lockean abstractionism. Namely the notion that you can get general ideas in themselves by erasing the specifics of a singular object. For George Berkeley, a general idea is nothing but the convergence of singular objects to which it refers, it does not have its own independent existence, not even as an object of thought. Berkeley is adamant, we do not think of a "tree in itself" (that is to say the one tree without any specificities), but the sum of individual trees. In 1712 Berkeley published Passive Obedience, bringing his idealism to moral and political philosophy.
As a devoted believer of God, Berkeley felt that materialism was dangerous because it promoted skepticism by questioning the validity of our senses. Berkeley thought that materialism also promoted atheism as it discounts the importance of God, trying to show that the world could run without his assistance. When Berkeley was appointed as Anglican Dean of the city of Derry in May 1724, he resigned his position at Trinity College. However, Berkeley was actually very involved during that time in the establishment of a seminary in Bermuda so he was never actually a Dean in residence. Berkeley soon left for Newport, Rhode Island in America on August 1st 1728 with his new bride, Anne Foster. Even though Berkeley had secured private donations for a new seminary, he waited three years, unfortunately in vain, for the grant for his seminary project. Regardless, Berkeley made good use of his time, as an acting cleric and continuing his writing. Berkeley wrote most of Alciphron, also known as The Minute Philosopher, which defended Christianity against freethinking, during that time. Berkeley met many prominent American intellectuals. Yet without the necessary political support for the Bermuda seminary, they canceled the project and Berkeley and his wife returned to Britain in 1731. Berkeley continued his humanitarian work in London in which he participated in establishing a home for abandoned children.
Back in London, Berkeley became very busy with his writing. Berkeley focused on writing a defense of his earlier work on vision entitled The Theory of Vision, Vindicated and Explained (1733). Berkeley then wrote The Analyst: a Discourse Addressed to an Infidel Mathematician (1734), a cutting critique of the foundations of Newton’s calculus. This critical work on the foundations of science would be very influential for the subsequent development of mathematics. Berkeley published other prodigious works such as A Sermon preached before the incorporated Society for the Propagation of the Gospel in Foreign Parts(1732), A Defence of Free-thinking in Mathematics, with Appendix concerning Mr. Walton's vindication of Sir Isaac Newton's Principle of Fluxions (1735), Reasons for not Replying to Mr. Walton’s Full Answer (1735), and revised editions of the Principles and the Dialogues in 1734.
George Berkeley was widely considered to be a good bishop concerned with both Protestants and Catholics. Berkeley had been made Bishop of Cloyne, Ireland in 1734 and mostly remained there until his retirement in 1752. While in Cloyne he wrote the most successful book of his lifetime entitled Siris (1744). The work primarily dealt with the medical virtues of tar-water, as well as the contemplation of God. Berkeley later moved to Oxford to oversee the education of his son George, one of his three surviving children. Soon after Berkeley died suddenly at the age of 67 on January 14th 1753 in Oxford and is buried there at Christ Church Cathedral.The city of Berkeley in California, was named in George Berkeley’s honor, but the pronunciation of the name evolved to suit American English. A residential college at Yale University also bears the philosopher’s name.