George Berkeley: seeing, matter and the limits of certainty

George Berkeley’s philosophy begins with a difficult question: what does it mean to say that something exists apart from every mind that could perceive it? His answer was radical, but often caricatured. Berkeley did not claim that tables and trees vanish when people leave the room. He argued against the idea of an unknowable material substance behind the qualities we experience, and held that the ordered world continues to exist because it is perceived by God. In asking readers to examine what they actually know, he made perception itself a central philosophical problem.

Born in Ireland, educated at Trinity College Dublin and ordained in the Church of Ireland, Berkeley also spent important periods in England and America. He was an Anglo-Irish philosopher, not simply an English or British one. His work crossed the intellectual and institutional worlds of Ireland and Britain, while his arguments travelled further. His legacy also includes a grave moral contradiction: he owned enslaved people and defended slavery. The reach of his thought and the difficulty of his record both belong in a truthful account.

Learning to see

Berkeley was born on 12 March 1685 at Dysart Castle, near Thomastown in County Kilkenny. He was the eldest son of William Berkeley and the oldest of six brothers. He attended Kilkenny College before entering Trinity College Dublin, where he was elected a scholar in 1702. He took his bachelor’s degree in 1704 and his master’s degree in 1707, the year he became a junior fellow. He remained at Trinity as a librarian, lecturer in Greek and preacher. Those years placed him within a college culture in which philosophy, theology, mathematics and the study of nature overlapped.

His first work to bring him notice was An Essay Towards a New Theory of Vision, published in 1709. Berkeley questioned the assumption that sight gives us distance, size and position directly. We do not see depth as though the eye were a measuring instrument. Instead, visual cues acquire meaning through experience: we learn to associate what we see with what touch and movement confirm. Seeing, in this account, involves interpretation and habit as well as sensation.

Berkeley’s argument was that distance is not itself visible. We learn to judge it through signs that experience connects with touch and movement. A visual appearance may therefore tell us something about how near an object is without giving us a direct view of distance as such. He also disputed the idea that we first see an object’s size and then calculate its distance, or the reverse: his account treated visual cues as learned signs that can inform judgements of both.

This was not a claim that the world is whatever anyone chooses to imagine. Berkeley was interested in how people learn to navigate a world whose appearances are regular and shared. What we see can act as a sign of what we may feel or encounter. His account helped make perception a subject for philosophical investigation in its own right: a process involving sensation, judgement and learned connections, rather than a passive window onto reality.

Berkeley’s earliest writing also included mathematical works, and his interest in signs and ideas would recur in later disputes about science and mathematics. The essay on vision established a lasting theme: before claiming to know what lies behind experience, we should be clear about what experience actually gives us. The importance he assigned to the relation between sight and touch also helps explain why his philosophy cannot be reduced to the slogan that nothing exists.

What does it mean for matter to exist?

Berkeley developed his questions about experience in A Treatise Concerning the Principles of Human Knowledge (1710) and, three years later, Three Dialogues Between Hylas and Philonous. These works set out what came to be called immaterialism or subjective idealism. The dialogue gives the argument a human shape: Hylas represents the materialist position, while Philonous presents Berkeley’s case. The treatise lays out the argument; the dialogue offers a further defence.

Our knowledge of an apple, Berkeley reasoned, comes through qualities such as its colour, shape, taste and firmness. If we remove every quality that can be perceived or conceived, what are we left with? He rejected the philosophical idea of material substance as an unknowable support for those qualities. To invoke something that, by definition, cannot be experienced was not, he thought, to explain experience. His challenge was directed at a theory of matter, not at the everyday reality of the objects people see and touch.

That argument is often compressed into the Latin phrase esse est percipi — to be is to be perceived. Berkeley’s position, however, was not that ordinary things are unreal. He accepted the reality of what people perceive. What he denied was that such things must be grounded in a mind-independent material substance of the kind philosophers proposed. For Berkeley, reality consists of active minds and the ideas they perceive; ideas are passive, while minds perceive and act.

His account also answered the obvious question of what happens to a room when nobody is looking. The world does not disappear, because God perceives it continuously. In Berkeley’s Christian philosophy, God is the source of the ordered and vivid experiences that do not depend on an individual’s will. Readers need not share that theology to understand the structure of the argument: Berkeley sought to account for permanence and common experience without accepting matter as an invisible foundation.

Berkeley’s early reception was difficult. His first principles were widely rejected, and his argument was treated with ridicule by some contemporaries, even as others acknowledged his intellectual ability. Yet a philosopher can matter without persuading everyone. Berkeley became a central figure in the empiricist tradition because later thinkers had to engage with the questions he raised about perception, abstraction and the limits of knowledge. His arguments formed part of the intellectual setting in which David Hume and Immanuel Kant wrote.

His books also make a demanding philosophical position accessible through examples and dialogue. The apparent simplicity of the question — what is left when every perceivable quality is removed? — leads to a difficult account of minds, ideas and divine perception. That combination of plain language and ambitious argument helped make Berkeley’s work an enduring point of dispute, rather than an isolated exercise in denying common sense.

Testing the language of science and mathematics

Berkeley extended his criticism of unexplained assumptions into natural philosophy. In De Motu (1721), he challenged Newtonian accounts of absolute space, time and motion. He objected to explanations that relied on forces or principles whose meaning, he argued, was unclear or beyond experience. His concern was not to reject scientific investigation, but to ask what its concepts explained and whether they could be tied to observable phenomena. He argued that a theory’s usefulness in organising experience did not settle every metaphysical question about what lay behind it.

He brought similar scrutiny to calculus in The Analyst (1734), addressed to a mathematician who was also a religious sceptic. Berkeley did not dispute that the new mathematics produced useful results. He questioned the foundations on which some calculations relied, particularly the treatment of infinitesimal quantities as though they could be both something and nothing. His phrase “ghosts of departed quantities” gave memorable form to the objection.

Berkeley did not overturn calculus. His critique belongs instead to the history of demands for greater clarity about mathematical reasoning. Later mathematicians developed more rigorous approaches to analysis, and his criticisms did not amount to a rejection of the results calculus could produce. The episode shows him applying the same pressure he brought to metaphysics: success in practice, he insisted, did not remove the need to explain the principles behind it.

His writing ranged beyond these best-known disputes. In Alciphron (1732), he addressed religion, morality and free-thinking through a series of dialogues. He also wrote on passive obedience and addressed magistrates. As a churchman, Berkeley did not separate questions about knowledge from questions about religious belief and conduct. His intellectual life took place in an age when those subjects were argued in colleges, churches and print, and his work moved between them.

College plans, public questions and a bishop’s work

Berkeley’s career began in Ireland’s learned and ecclesiastical institutions. He was ordained as a deacon in 1709 and as a priest in 1710. In 1721 he took a doctorate in divinity and remained at Trinity College Dublin, lecturing in divinity and Hebrew. He later became Dean of Dromore and then Dean of Derry. In 1734 he became Bishop of Cloyne in the Church of Ireland, a post he held until his death. His career joined teaching and philosophical writing to a continuing role in church life.

In 1725 Berkeley began a plan to establish a college in Bermuda for the training of ministers and missionaries. He gave up the income attached to his deanery in pursuit of the project. After marrying Anne Forster in London in 1728, he went to America with her, travelling on a salary of £100 a year. The anticipated funds for the college did not arrive. He lived in Rhode Island while waiting for them, then left America and returned to London in 1732. The scheme joined an educational ambition to a missionary purpose and must be understood in its colonial setting.

Berkeley’s public concerns also turned to economic conditions in Ireland. After his return from America, he wrote The Querist, a work largely composed of questions about poverty, labour, trade and the country’s resources. Its form is significant: instead of presenting one continuous treatise, Berkeley prompted readers to examine the arrangements and assumptions behind their society. The supplied account of his economic proposals includes a scheme for paper currency issued by a publicly owned central bank. This practical concern for Ireland’s economy sits alongside, rather than replacing, his philosophical writing.

He also took part in efforts to establish a home for abandoned children in London. The Foundling Hospital received its royal charter in 1739, and Berkeley was among its original governors. This provides another example of his involvement in public affairs beyond the pulpit and the college. It should not be turned into a simple story of benevolence, however: public activity and intellectual distinction do not settle the moral questions raised by other parts of his life.

Berkeley’s final years included further writing on tar-water. Siris, published in 1744, linked reflections on the supposed virtues of tar-water with wider philosophical subjects; he returned to it in a later work published in 1752. He retired from Cloyne in 1752 and went to Oxford with his wife and daughter Julia, where he joined his son George and supervised his education. He died in Oxford on 14 January 1753 and was buried in Christ Church Cathedral.

A distinguished mind and a troubled inheritance

Berkeley’s American project and his life in Rhode Island cannot be separated from the history of slavery. While there, he bought a plantation at Middletown and purchased several enslaved Africans to work on it. He also defended slavery in his writing. The college scheme had a missionary purpose, but that purpose does not make the institution or the society in which it was conceived free of colonial power and exploitation.

Trinity College Dublin stated in 2023 that Berkeley was both an owner of enslaved people and a theorist of slavery. That year, the university removed his name from one of its libraries; the library was subsequently named for the poet Eavan Boland. This decision makes plain that Berkeley’s public memory is not simply a record of books and philosophical influence. It is also a question of what institutions choose to commemorate and how they explain the histories attached to that commemoration.

His intellectual contribution does not excuse his ownership of enslaved people or the positions he defended. Nor does that moral failure erase the historical importance of his work on vision, matter, science and public questions. A responsible account has to keep both facts in view without treating them as items that can cancel one another. Berkeley’s writings invite scrutiny of assumptions; his life, too, requires scrutiny rather than unexamined admiration.

Why George Berkeley deserves a place in British Legacy

George Berkeley deserves a place in British Legacy because the intellectual history of Britain and Ireland cannot be divided neatly along modern national lines. Born in County Kilkenny, educated at Trinity College Dublin and ordained in the Church of Ireland, he also spent consequential years in London and Oxford. His career connected Irish colleges and churches with debates that circulated more widely. Calling him Anglo-Irish recognises that history without claiming him as an uncomplicatedly British figure. The connection is specific: his education, religious office and writing belonged to institutions and arguments that linked Ireland and Britain.

His achievement lies in the range and force of the questions he left behind. Berkeley asked how people learn to see, what they mean by matter, and whether scientific and mathematical explanations are clear about their foundations. He made the ordinary world philosophically strange without simply denying its reality. His challenge to theories of material substance made later thinkers reckon with the limits of perception and knowledge; his criticism of calculus insisted that successful methods deserve clear principles as well as useful results. His account of vision, meanwhile, treated seeing as something shaped by experience and learned associations, not a transparent copy of the world.

Berkeley also brought philosophical attention to public life. Through The Querist, he asked questions about Ireland’s poverty, labour and economic arrangements. His college plan and his work as a Foundling Hospital governor show a career extending beyond philosophical treatises, although neither should be used to obscure the colonial and slave-owning history of his American years. His public legacy is therefore not a simple tale of enlightened service: it includes projects and actions that must be examined in their context.

Remembering Berkeley responsibly means neither erasing his intellectual contribution nor allowing it to shelter his actions from scrutiny. His ownership of enslaved people and defence of slavery are essential parts of the record, as is Trinity College Dublin’s decision to remove his name from its library. The case for including him is not that he offers a spotless monument. It is that his work and life illuminate how ideas travelled through institutions, how argument can challenge assumptions, and how intellectual distinction does not guarantee moral insight. Those are meaningful reasons to preserve his place in the intertwined histories of Ireland and Britain.

Sources

George Berkeley — Wikipedia, revision 1370236997 · George Berkeley — Wikipedia

Adapted in part from George Berkeley by Wikipedia contributors, under CC BY-SA 4.0. Text has been edited and combined with the existing article; this adapted text is shared under the same licence. Contributor history.