George Berkeley

George Berkeley books and biography


George Berkeley

Name: George Berkeley
Birth: 12 March 1685
Death: 14 January 1753
School/tradition: Idealism, Empiricism
Main interests: Idealism, Empiricism
Influenced: David Hume

George Berkeley (IPA: /ˈbɑː(ɹ).kli/) (12 March 1685 – 14 January 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"). The theory states that individuals can only directly know sensations and ideas of objects, not abstractions such as "matter". 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 and Hylas, named after the ancient Greek word for matter, representing the ideas of Locke). In 1734 he published The Analyst, a critique of the foundations of science, which was very influential in the subsequent development of mathematics.

The city of Berkeley, California is named after him, by virtue of it growing up around the university there that was named after him, but the pronunciation of its name has evolved to suit American English. A residential college in Yale University also bears his name, as does the copyright library at Trinity College Dublin.



Berkeley was born in County Kilkenny and grew up at Dysart Castle, near Thomastown, Ireland, the eldest son of William Berkeley, a cadet of the noble family of Berkeley. He was educated at Kilkenny College and 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. His earliest publication was a mathematical one; but the first which brought him into notice was his Essay towards a New Theory of Vision, published in 1709. Though giving rise to much controversy at the time, its conclusions are now accepted as an established part of the theory of optics. There next appeared in 1710 the Treatise concerning the Principles of Human Knowledge, which was followed in 1713 by Dialogues between Hylas and Philonous, in which he propounded his system of philosophy, the leading principle of which is that the world as represented to our senses depends for its existence, as such, on being perceived. Of this theory the Principles gives the exposition and the Dialogues the defence. One of his main objects was to combat the prevailing materialism of the time. The theory was largely received with ridicule, though some, such as Dr. S. Clarke, considered him a genius. Shortly afterwards he visited England, and was received into the circle of Addison, Pope, and Steele. 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 1724 he was made Dean of Derry.

In 1725 he formed the project of founding a college in Bermuda for training ministers for the colonies, and missionaries to the Indians, in pursuit of which he gave up his deanery with its income of £1100, and went to America on a salary of £100. He landed near Newport, Rhode Island where he bought a plantation - the famous "Whitehall." On October 4, 1730, Berkeley purchased "a Negro man named Philip aged Fourteen years or thereabout." A few days later he purchased "a negro man named Edward aged twenty years or thereabouts." On June 11, 1731, "Dean Berkeley baptized three of his negroes, 'Philip, Anthony, and Agnes Berkeley' " (The bills of sale can be found in the British Museum (Ms. 39316). See George C. Mason, Annals of Trinity Church, 1698-1821, 51).

Berkeley's sermons explained to the colonists why Christianity supported slavery, and hence slaves should become baptized Christians: "It would be of advantage to their [slave masters'] affairs to have slaves who should 'obey in all things their masters according to the flesh, not with eye-service as men-pleasers, but in singleness of heart, as fearing God;' that gospel liberty consists with temporal servitude; and that their slaves would only become better slaves by being Christian" (Berkeley, Proposal, 347. See his sermon in Newport, preached October, 1729).

He lived at the plantation while he waited for funds for his college to arrive. The funds, however, were not forthcoming and in 1732 he returned to London. In 1734, he was appointed Bishop of Cloyne. Soon afterwards he published Alciphron, or The Minute Philosopher, directed against Shaftesbury, and in 1734-1737 The Querist. His last publications were Siris, a treatise on the medicinal virtues of tar-water, and Further Thoughts on Tar-water.

He remained at Cloyne until 1752, when he retired and went to Oxford to live with his son. His affectionate disposition and genial manners made him much loved and held in warm regard by many of his contemporaries. He is buried in Christ Church Cathedral.

Contributions to philosophy

Berkeley's theorizing was empiricism at its most extreme. In his first publication, regarding vision, he stated that we only really perceive two spatial dimensions, height and width. The third, spatial, dimension of depth is not directly known; rather, it is inferred by the mind. As a young man, Berkeley theorized that individuals cannot know if an object is, individuals can only know if an object is perceived by a mind. He stated that individuals cannot think or talk about an object's being but rather think or talk about an object's being perceived by someone; individuals cannot know any "real" object or matter "behind" the object as they perceive it, which "causes" their perceptions. He, thus, concludes that all that individuals know about an object is their perception of it.

Under his empiricism, the object individuals perceive is the only object that they know and experience. If individuals 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 raises the question whether this perceived object is "objective" in the sense of being "the same" for fellow humans, in fact if even the concept of other human beings, beyond individual perception of them, is valid. Berkeley argues that since an individual experiences other humans in the way they speak to him —something which is not originating from any activity of his own —and since they learn that their view of the world is consistent with his, he can believe in their existence and in the world being identical or similar for everyone.

It follows that:

  1. Any knowledge of the empirical world is to be obtained only through direct perception.
  2. Error comes about through thinking about what individuals perceive.
  3. Knowledge of the empirical world of people and things and actions around them may be purified and perfected merely by stripping away all thought, and with it language, from their pure perceptions.

From this it follows that:

  1. The ideal form of scientific knowledge is to be obtained by pursuing pure de-intellectualized perceptions.
  2. If individuals 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.
  3. The goal of all science, therefore, is to de-intellectualize or de-conceptualize, and thereby purify, human 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 continues to exist in the Quad when "nobody" is there simply because God is an infinite mind that perceives all.

The philosophy of David Hume concerning causality and objectivity is an elaboration of another aspect of Berkeley's philosophy. As Berkeley's thought progressed, he may have almost entirely assimilated his theories to those of Plato, though this is far from certain. Luce, the most eminent Berkeley scholar of the twentieth century, constantly stressed the continuity of Berkeley's mature philosophy. This suggests a continuity between the Principles, Alciphron and the rest of Berkeley's philosophical works. Furthermore, Berkeley’s unwavering panentheism is evidence that counts against a complete assimilation with Platonism, and Alciphron is a development rather than a revision of anything in the earlier works. The fact that the main works were re-issued just a few years before Berkeley's death without major changes also counts against any theory which attributes to him a volte-face.

Over a century later Berkeley's thought experiment was summarised in a limerick and reply by Ronald Knox;

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."
"Dear Sir, your astonishment's odd;
I am always about in the Quad
And that's why this tree
Will continue to be
Since observed by Yours faithfully, God."

In reference to Berkeley's philosophy, Dr. Samuel Johnson kicked a heavy stone and exclaimed, "I refute it thus." A philosophical empiricist might reply that the only thing that Dr. Johnson knew about the stone was what he saw with his eyes, felt with his foot, and heard with his ears. That is, the existence of the stone consisted exclusively of Dr. Johnson's perceptions. It might be possible that Dr. Johnson had actually kicked an unusually grey tree stump, or perhaps that a sudden attack of arthritis had flared up just when he was about to kick a random patch of grass with a painting of a rock. Whatever the stone really was, apart from the sensations that he felt and the ideas or mental pictures that he perceived, was completely unknown to him. The kicked stone existed, ultimately, as an idea in his mind, nothing more and nothing less.

Berkeley shows this in the Dialogues by saying we define an object by its primary qualities and its secondary qualities. He takes an example of a secondary quality, heat. If you put one hand in a bucket of cold water, and your other hand in a bucket of warm water, then put both hands in a bucket of luke warm water, one of your hands is going to tell you that the water is cold and the other that the water is hot. Berkeley says that since two different objects (your hands) perceive the water to be hot and cold, then the heat is not a quality of the water.

Primary qualities are treated the same way. Berkeley says that size is not a quality of an object because the size of the object depends on the distance between the observer and the object, or the size of observer. Since an object is a different size to different observers, then size is not a quality of the object. Berkeley refutes shape with a similar argument, then asks: if neither primary qualities nor secondary qualities are of the object, then how can we say that there is anything more than the qualities we observe?

Berkeley's Treatise Concerning the Principles of Human Knowledge was published three years before the publication of Arthur Collier's Clavis Universalis, which made assertions similar to those of Berkeley. However, there seemed to have been no influence between the two writers.

German philosopher Arthur Schopenhauer once wrote of him: "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...." (Parerga and Paralipomena, Vol. I, "Fragments for the History of Philosophy," § 12)

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 indirect 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 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 defence 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.

See also

  • De Motu (on Motion), an essay published in 1721.
  • Tlön, Uqbar, Orbis Tertius
  • List of people on stamps of Ireland


Primary: Ewald, William B., ed., 1996. From Kant to Hilbert: A Source Book in the Foundations of Mathematics, 2 vols. Oxford Uni. Press.

  • 1707. Of Infinites, 16-19.
  • 1709. Letter to Samuel Molyneaux, 19-21.
  • 1721. De Motu, 37-54.
  • 1734. The Analyst, 60-92.


  • This article incorporates public domain text from: Cousin, John William (1910). A Short Biographical Dictionary of English Literature. London, J.M. Dent & sons; New York, E.P. Dutton.
  • Stanford Encyclopedia of Philosophy: George Berkeley by Lisa Downing.

This article might use material from a Wikipedia article, which is released under the Creative Commons Attribution-Share-Alike License 3.0.

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