The Works of George Berkeley. Vol. 1 of 4: Philosophical Works, 1705-21

In Short

This volume collects the foundational early writings of George Berkeley, in which he outlines his radical philosophy of immaterialism. Through early notebooks, formal essays, treatises, and philosophical dialogues, Berkeley challenges the prevailing belief that physical objects exist independently of mind and perception. He argues that what we call the material world consists entirely of visual and tactual sensations, or "ideas," which have no existence outside a perceiving mind. Far from promoting skepticism, Berkeley presents his view as a restoration of common sense: distance is an learned inference rather than a direct visual perception, physical laws are regularities established by God, and the physical world derives its reality from being continuously perceived by an omnipresent Creator. This collection has endured because it fundamentally shifted Western metaphysics, forcing philosophers to re-examine the relationship between human perception, physical reality, and the nature of mind.

The Story

The argument of this collection unfolds as a progressive dismantling of materialist assumptions, beginning with private reflection, moving through the psychology of perception, and culminating in a comprehensive metaphysical system.

The volume opens with Berkeley’s private working notes, where he records his earliest insights into the nature of reality. He reflects on the traditional philosophical distinctions between real objects and mental concepts, noting how previous thinkers have become entangled in abstractions. In these early entries, he sets out to recall philosophy to common sense by grounding all knowledge in immediate experience. He questions the existence of abstract ideas—such as shape or motion existing apart from any specific object—and insists that whatever we perceive must be a concrete, particular sensation.

From these initial reflections, the focus shifts to the mechanics of human vision. Berkeley analyzes how we perceive space, depth, and distance. He demonstrates that the eye does not directly measure distance, because distance is merely a line projected endwise against the retina, registering as a single point. Instead, our belief that we see things at a distance is an inference formed through long experience. We learn to associate visual cues—such as color, faintness, and visible figure—with the physical movements and touch sensations that follow. Light and color belong to sight, while resistance and extension belong to touch; there is no single, shared property observed by both senses simultaneously. Vision acts as a visual language, allowing us to anticipate tactile experiences based on what we see.

Building upon this foundation, Berkeley expands his inquiry from visual perception to the entirety of the material world. He attacks the traditional distinction between primary qualities (such as shape, size, and motion) and secondary qualities (such as color, sound, and heat). While earlier philosophers acknowledged that colors and heats exist only in the mind of the percipient, Berkeley argues that the exact same logic applies to primary qualities. Figure, extension, and motion vary depending on the observer’s position, sight, or frame of mind; they cannot be images of a static, unperceived material substance existing outside of consciousness. Consequently, physical objects are nothing more than collections of sensible qualities, or ideas, that exist only while being perceived.

This view naturally raises the question of what happens to the world when no human is looking at it. Berkeley resolves this by identifying the true cause of our sensations. Because human beings are not the authors of their own sensory experiences—we cannot simply choose what to see or hear when we open our eyes—these sensations must be produced in us by an active, external cause. That cause cannot be inert matter, which possesses no active power. It must be an infinite, incorporeal Spirit. Physical laws are simply the orderly, predictable sequences in which God presents these ideas to our minds.

To address potential objections, the argument is recast into a dramatic dialogue between two figures: Hylas, a defender of material substance, and Philonous, a proponent of immaterialism. Philonous systematically dismantles Hylas’s arguments. He demonstrates that intense heat is indistinguishable from pain, and since pain can exist only in a perceiving mind, heat must be equally mental. When Hylas attempts to salvage matter by defining it as an underlying "substratum" that supports qualities without being seen itself, Philonous shows that a substratum distinct from extension is a self-contradictory concept. Step by step, Hylas is forced to abandon his reliance on hidden physical causes, unperceived instruments, and abstract matter, eventually accepting that all reality is mental and sustained by God.

Finally, the volume examines the nature of physical motion and force. Berkeley criticizes contemporary physics for treating concepts like "gravity," "force," and "attraction" as hidden physical entities residing within bodies. He maintains that terms like force are useful mathematical tools for calculating motion, but they do not denote hidden physical realities. In natural philosophy, physical explanation consists of describing mechanical rules and observed patterns, such as the equality of action and reaction, rather than inventing unobservable material causes. True agency belongs exclusively to spirit, which originates all motion and sustains the physical universe.

How It Unfolds

The private groundwork Berkeley records his initial philosophical breakthroughs, rejecting abstract ideas and resolving to bring philosophy back to common sense. He insists that things are real as experienced, and that abstract concepts like mindless matter create unnecessary skepticism.

Analyzing the mechanics of sight He examines how human visual perception operates, demonstrating that distance itself cannot be seen directly by the eye. Visual experience consists solely of light and color, which the mind learns to connect with tactual and locomotive experiences through repeated association.

Refuting abstract material substance Expanding his theory to all physical objects, he argues that primary qualities like shape and motion depend on the percipient just as much as secondary qualities like heat and color. Physical items are shown to be combinations of sensible ideas rather than external, mindless matter.

Establishing the divine cause Because our sensory ideas are not created by our own wills, they must be produced in us by an active external cause. Inert matter cannot cause anything, leaving an omnipresent, infinite Spirit as the sole immediate source of all sensory phenomena and natural order.

Debating the defender of matter In a series of dialogues, Philonous confronts Hylas, systematically dismantling every definition of material substance. Philonous demonstrates that matter cannot serve as a substratum, an instrument, or an unperceived reality, forcing Hylas to admit that reality is entirely spiritual.

Redefining physical force and motion He critiques the physics of his day, arguing that concepts like force and gravity are mathematical abstractions rather than hidden physical entities. True causation belongs to mind alone, while physics properly focuses on cataloging observable mechanical laws.

The People

Philonous The primary spokesman for Berkeley’s philosophy in the dialogues. He seeks to overthrow the belief in unperceived material substance, arguing that true reality consists of perceiving minds and their ideas. Philonous wants to eliminate the room for atheism and skepticism created by materialist theories. He remains patient and methodical, guiding his opponent through logical steps until Hylas recognizes that sensory experience requires a divine, governing mind.

Hylas The representative of traditional philosophical opinion and common-sense materialism. He initially believes that physical objects exist independently of any mind and that sensory qualities reside directly in material bodies. Throughout the dialogues, Hylas struggles to preserve some form of independent matter—first as primary qualities, then as an unperceived substratum, and finally as a passive instrument used by God. By the end, he surrenders his assumptions, coming to see immaterialism as the true defense of knowledge and religion.

George Berkeley The author whose developing thought frames the volume. Motivated from his youth by a desire to refute skepticism and free-thinking, he aims to demonstrate the immediate presence of God in daily perception. He sees abstract philosophical terminology as a source of confusion and seeks to realign philosophy with simple human experience.

Alexander Campbell Fraser The nineteenth-century editor whose prefaces and annotations contextualize Berkeley’s writings. Fraser traces Berkeley’s biographical path from Trinity College, Dublin, through his travels in London and Rhode Island, to his later years as Bishop of Cloyne. He highlights how Berkeley’s early speculative genius matured into a focused defense of divine moral order.

In Its Own Voice

"Mem. To be eternally banishing Metaphisics, &c., and recalling men to Common Sense."

Berkeley records this simple, resolute directive in his early private notes, framing his lifelong philosophical mission to strip away complex abstractions and return to immediate human experience.

"Looking at an object, I perceive a certain visible figure and colour, with some degree of faintness and other circumstances, which, from what I have formerly observed, determine me to think that if I advance forward so many paces, miles, &c., I shall be affected with such and such ideas of touch."

Here Berkeley explains the core of his visual theory, demonstrating that seeing an object at a distance is not a direct perception of depth, but a learned expectation of future physical movements.

"Take away this material substance—about the identity whereof all the dispute is—and mean by body what every plain ordinary person means by that word, to wit, that which is immediately seen and felt, which is only a combination of sensible qualities or ideas: and then their most unanswerable objections come to nothing."

In this passage from his main philosophical treatise, Berkeley argues that discarding the hidden concept of "matter" does not destroy the physical world, but preserves it as the concrete reality we directly see and feel.

What It's Really About

At its core, this volume is an assault on the concept of abstract, unperceived matter. Berkeley targets the widely held philosophical assumption that behind the colors, sounds, textures, and shapes we experience lies an unthinking, material substance that exists independently of mind. He demonstrates that such a substance is not only unobservable, but logically inconceivable, as one cannot conceive of an unperceived object without simultaneously conceiving it in their mind.

The book also addresses the origins of philosophical skepticism. Berkeley argues that when philosophers separate the world as it appears to us from the world as it "really is" in itself, they create an unbridgeable gap between human perception and truth. By identifying the reality of things with their being perceived—summarized in the principle esse est percipi—he eliminates this gap. Physical things are precisely what we experience them to be, not distant representations of hidden material causes.

Finally, the work is a defense of divine providence. By proving that inert matter cannot cause our sensations or maintain the regular laws of nature, Berkeley concludes that the physical universe is an ongoing, direct communication from God to human minds. Every sight, sound, and touch becomes part of a continuous divine language.

Why Read It Today

Berkeley's early writings remain remarkably readable and provocative. Unlike many dense metaphysical treatises of the eighteenth century, his works—particularly the Essay Towards a New Theory of Vision and the Three Dialogues—are written with exceptional clarity, vigor, and literary grace. The dialogue form allows readers to watch common objections raised and systematically answered in real time, making the argument feel accessible and engaging rather than dryly academic.

Reading Berkeley today offers a refreshing jolt to our everyday assumptions about reality. His analysis of visual perception anticipates modern cognitive science and psychology, showing how much of what we consider direct sight is actually rapid mental interpretation. For anyone interested in metaphysics, philosophy of mind, or the history of ideas, his work provides a foundational challenge: testing whether one can actually prove the existence of a material world outside of perception.

The book does present occasional hurdles for modern readers. The volume includes Latin texts, such as De Motu, along with scholarly prefaces and historical footnotes that reflect nineteenth-century editorial interests. Additionally, Berkeley's early working notes contain abbreviated, fragmented thoughts that require careful reading. Yet despite these historical layers, Berkeley’s core voice remains direct and lively. Readers who enjoy sharp logic, brilliant prose, and arguments that turn common assumptions upside down will find this volume deeply rewarding.