Problems of Idealism | George Berkeley

Jubilee Nunnallee 6/1/2019

“The faculty of being acquainted with things other than itself is the main characteristic of a mind.”
― Bertrand Russell

Idealism (philosophy), is a central philosophical notion of mind and spirit that constitutes the fundamental aspects of reality. Adherers of this metaphysical philosophy think of reality as being a product of the mind rather than the inverse (i.e. the mind being a product of reality). Note: This theory should not be confused with platonism or platonic idealism because Plato’s theory was that ‘ideas’ or universals are more real than there particulars.

An Irish priest, George R. Berkeley (1685-1753) of the Church of Ireland, developed the fundamental theory of immaterialism known today as subjective idealism. He begins to develop this theory writing in a collection of notes he never meant to publish. These notes later became known as the Philosophical Considerations. His first major work: An Essay Towards a New Theory of Vision (1709). This is where he develops a concept that would later become the crux of immaterialism (the heterogeneity thesis.) In his conception of sight, distance, and the station of objects, Berkeley concludes that these phenomena are subjective and relative in perception. Not yet concluding that objects are a product of the mind but of tangible objects being relative to the perceivers sensual qualities. His works were never popular during his life-time despite one pseudo-scientific essay he wrote on the medicinal uses of tar-water (Siris). Posthumously, two of his works later became popular, Treaties (1710). (Original title: A Treatise Concerning the Principles of Human Knowledge and Three Dialogues (1713). (Original title: Three Dialogs between Hylas and Philonous.) These works would develop immaterialism or idealism in principle and would lay the philosophical foundation that shaped what most of the theory is today.

Here are a few key terms you should know:

  • Subjective idealism/immaterialism: rejects the notions that objects can exist independently of human perception and are dependent on a mind to exist.
  • Objective idealism: accepts that objects exist, even to the extent that objects are independent of human perception, but denies that the mind & spirituality are products of reality. Objective idealism thus opposes naturalism and realism.
  • Naturalism & Realism: infers that all objects and its fundamental properties are material, (materialism).
  • Occasionalism: a theological tenet that believes causal events to not occur naturally but are consummated by a supreme deity (God) via creation and conservation.

Berkeley coined the term “esse est percipi – to be is to be perceived”; which has become a kind of motto for idealist theoreticians. This motto hints to the underlining presupposition that all qualities attributed to objects are part of the spirit or sense qualities. Thus, hardness is the sensing of a resistance rather than its mass density D, and heaviness is a sensation of muscular effort rather than its pound or force lbf (Duignan n.d.). A major criticism of Berkeley’s theory was how objects manifest and demanifest themselves in accordance with our experience and perception of them. In an essay entitled De Motu, Berkeley attempts to justify that all objects are a product of God’s mind as he is the ultimate perceiver. Borrowing from occasionalist rhetoric, objects would retain its physical properties as eternally being perceived by an omniscient and omnipresent deity (conservationism). As a theory immaterialism has been criticized roundly by academics and even some of Berkeley’s contemporaries. Dr. Samuel Johnson is said to have held strong opposition to Berkeley’s theory. In his biography he is quoted as saying “I have refuted it thusly, while kicking a rock”, (Boswell 1791). The kicking of the rock is a metaphor for how objects react and interact with its environment. So, I see something in my environment and I interact with it then I expect it to behave according to its fundamental properties and the basic laws of physics. Our sense qualities and direct perception of objects around us would later become the principle of naive realism, (philosophical). But in terms of realism we can grasp why idealism is problematic by simply attacking it at its foundation. Because it is self contradictory to claim that reality is a product of a mind. This is because idealism rests on an Is statement. A description of something based in reality (a mind) so it already presupposes realism. To presume that all things are ontologically continent on a mind would infer that the mind is a fixed entity grounded in reality. Before we could begin to doubt our interpretation of reality we must axiomatically assume the very real existence of the object we are inferring from. This axiom is repeated in Cartesian philosophy ipsissima verba: “cogito ergo sum,” “I reflect therefore I am.” To use a turn of phrase if one wanted to dismiss subjective idealism outright one may simply tug at this loose thread and the whole theory comes undone.

As a naive realist, not to be confused with psychological naive realism, I don’t adhere to any idealistic theory. I fully accept the universal adage that everything is made of some kind of substance and material stuff. I would also agree that not all idealism can be easily dismissed. Take the argument for the intentional theory of perception & objective idealism. The intentional theory of perception would note that some instances of reality are mere fantasy, phantoms, and illusory perceptions. For instance, a pencil in a glass of water would show it as bent which is due to the refraction of light. With this anomaly our direct perception can turn out to be unreliable. This principle is closely related to the concept of naive realism (psychology) in which a persons beliefs tend towards a bias that reality is as it is directly perceived. You may recall the famous analogy known as the Gettier problem by the American philosopher Edmund Gettier Is Justified True Belief Knowledge, (1963). In this short essay Gettier asks the reader to imagine two potential employee’s interviewing for the same job. One hiree knows that the person who will get the job has ten coins in their pocket. But he observes ten coins in the pocket of the other potential employee. Armed with this verification he justifiably assumes that his conclusion must also be true, that he will not get the job. But to his astonishment he does get hired not knowing that he also had ten coins in his pocket. This analogy was fabricated to refute the long standing principle of justified true belief (JTB). Because it describes a possible situation in which a belief was verified with evidence which justified his conclusion. But in the end his conclusion was still wrong. I prefer the example of the earth orbiting the sun (heliocenterism). Because we generally accept this anomaly as truth, as it is what we have directly observed. But as it turns out the sun and earth revolve around the barycentre which is at the center of our solar system. The sun just happens to be near there but this obviously changes with its orbit. So you could argue that the earth is not actually revolving around the sun, but that both the sun and earth revolve around the barycentre. The barycentre can also be defined as being between two orbiting bodies of mass, like the moon and earth. I want to avoid getting too scientific with this example because I am not qualified to speak on astronomy. The point is to say that when we focus on our observation of anomalies we tend to believe what we directly perceive. This would not necessarily be an argument for immaterialism but it does show that relying too heavily on direct-perceptual knowledge can be problematic in some instances.

Objective idealism could also be reasonably argued for as ideas are said to be immaterial. This type of idealism asserts that ideas themselves are not objects and do not take up space in the material world. If I described my favorite band then that idea is said to be a product of my mind and not the physical world. The band exists (The Postal Service) but my bias can not be said to be a property of that ensemble nor could it be said to take up space in the material world. I recall an online debate I had about this topic in which another group member criticized me by saying his, “choice of dessert” did not take up space in the material world. My immediate response was to state a simple principle of physics, “that something physical cannot act or interact with something non-physical”. And his choice of dessert may be a product of his relative experience but its existence is necessarily dependent on his mind existing. If his mind did not exist then his choice of dessert would not exist. There are also several biological factors that contribute to personal taste. Scientifically, taste is caused by a mix of sensitive chemical reactions in the tongue. But other factors include “nature and nurture like our genes and environment”, (Leslie J. Stein, PhD). Lastly, while we may yet fully comprehend the complexity of our neurological faculties we do know that ideas are a function of a mind. To put it simply, if I conceived of an idea, (i.e. my choice of dessert), then that notion cannot be conceived of without the physical and chemical reactions happening within my brain. I will go further and say that a function of anything cannot itself be immaterial. This may be an argument for functionalism, but saying that a function of a mind can be immaterial is simply a performative contradiction. Like me screaming in your ear that sound does not exist. You may come up against competing ideas, such as emergentism. The conception that ideas are emergent properties and are not necessarily reducible to the physical properties of the mind, notwithstanding. Again, this is all conjectural and would not assume immaterialism but I have seen it argued. The hard problem of consciousness along with other theories of idealism are all still deeply contested issues amongst philosophers and other academics. But in terms of subjective idealism I have refuted it thusly.


Berkeley, G., (1710). A Treatise Concerning the Principles of Human Knowledge. London Press.

Berkeley, G., (1713). Three Dialogs between Hylas and Philonous. London Press.

Duignan, B., (n.d.). George Berkeley Irish Philosopher Retrieved from

Boswell, J., (1791). The Life of Samuel Johnson, LL.D. Penguin Classics.

Hatfield, H., (2005). The Science Behind How We Taste. Retrieved from

O’Brian, D., (n.d.). Objects of Perception. Retrieved from

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