Part one can be found here. This is part two of a three part series which reflects on Berkeleyan idealism in light of classical realism.

A foundational concept in Berkeley’s philosophy is that reality depends on a perceiver in order for it to be (the esse in his famous dictum). And this is the point of contention for classical realists. Is it correct to say that reality is structured in such a way that it must be perceived to exist? (Additionally, an outright denial of the existence of matter seems problematic and is, in fact, Gnostic.) Classical realism takes both perception and objective reality seriously because sense experience is the only connection one has to the world. The realist finds the entire project of proving an external world to be supremely uninteresting and quite unnecessary. Regarding the faculties of the mind, the act of perception is different from other cognitive abilities like thought, memory, or imagination. Thinking is not the same as having a sense perception. One can think through an issue or problem, recall a memory, or use one’s imagination (such as reading a work of fiction or pondering the existence of centaurs). When these faculties, or acts of the mind, are engaged one can always ask the additional reflective question of whether or not they exist in external reality. When it comes to the faculty of perception, however, one cannot separate one’s perception of an object from its actual existence in reality. Normal perception is always the perception of an external object. If that were not the case, there would be no difference between reality and hallucination. When one asks about hallucinations, external objective reality is assumed in the question, or it would not be a question.¹ Perception is what gives human beings the ability to distinguish between appearance and reality (in order to correct a faulty sense appearance, one simply has another sense experience). The faculty of imagination, however, consists of the ability to think of objects that do not exist in reality. In contrast, the faculty of perception is always of something, an external object. Classical realists hold that humans are cognitively structured to be of, about, and oriented towards reality. It makes little sense to say one has a physical perception of a tree and, at the same time, that the tree does not exist. The logical laws of non-contradiction, identity, and excluded middle still hold with sense perception. It does no good to deny external reality. When the mind works correctly, there is no need to prove an external world. Human perception is always of something. In metaphysical terms, that which is cannot be denied.

Berkeley’s conflation of thinking with perception utterly confuses the most important aspects of reality itself—the subjective and objective, appearance and reality, being and becoming, the one with the many, and ultimately equates thought, or mind, with Being. Instead of clarifying reality or explicating the nature of reality, Berkeley only adds more confusion to these ultimate questions. If Berkeley’s interpretive scheme of reality is correct, there is no way to explore the metaphysical nature of reality. The field of metaphysics, itself, would be impossible. The rejection of any reality external to one’s mind undermines the task of metaphysics which is to discover the objective first principles of being as being, at least according to the Aristotelian definition of metaphysics.

Further, classical realists hold to compresence—the idea that minds and objects are both part of reality and co-related. Because human beings live in a common world of sense, they can also share a common world of thought and intellectual engagement. As Alfred North Whitehead explains, “I do not understand how a common world of thought can be established in the absence of a common world of sense” (178). Human beings share the same basic reality and the mind is tuned to the concrete requirements of objective existence. Reality has its own intractable way of being and it is objectively intelligible, discoverable, and shareable with others through the tools of reason—sometimes by way of induction, other times by deduction, and sometimes both working together. Being itself is the unifying standard of all thought and physical activity. The realist, therefore, maintains that all thought and human action takes place in objective time and space.

As extreme as Berkeley appears to be, it is important to take a closer examination of his perspective, and we will explore this further in upcoming posts. For now, keep in mind that no great philosopher or author is completely wrong. Berkeley’s idealism forces one to think about the nature of reality at a deeper level. Perhaps one reason for including Berkeley as one of the great Western philosophers that (although epistemically wrong), he forces one to think more carefully, rationally, and critically about the most fundamental questions of reality. Even when a thinker is wrong, an examination of the position is still instructive. Berkeley raises several questions that the realist wisely takes seriously. How should one think about reality or being? What role does the mind have in knowing reality? And what are the ultimate principles of reality, if any?

While idealists such as Berkeley insist that reality is determined by the mind, or immaterial spirit, realists like Aristotle and Aquinas pose a different strategy for understanding reality and offer a way to think about being that neither denies the role of the mind, nor rejects external reality. When it comes to epistemology, realists believe that there must be first principles of knowledge. An examination of these first principles will demonstrate the role that the intellect plays in knowing reality. The first principles of knowledge are self-evident and foundational to all other knowledge.

All the sciences are derived from basic self-evident first principles. Aquinas puts it this way, “The principles of any science are either in themselves self-evident, or reducible to the knowledge of a higher science” (Ia, q. 1, a. 2 ). And, “The word ‘principle’ signifies only that from which another proceeds: For anything from which something proceeds in any way we call a principle” (Ia, q. 33, a. 1). Self-evident truths are principles that are foundational to all knowledge, and are impossible to deny (such as logical truth, the law of noncontradiction, mathematical truth such as the axioms of geometry, and moral truths such as the proposition that it is always wrong to rape women)². Self-evident truths are the starting points for any scientific or philosophical inquiry. First principles do not provide the content of reality, rather, they are what make knowledge of reality possible. Classical realists do not deny that the mind has a role when it comes to understanding reality.

Aquinas also refers to first principles that are reducible to the knowledge of a higher science. This occurs when, for example, one understands that music relies on mathematical formulas, or the scientific method rests on the ultimate metaphysical principles of the law of causality, law of predictive uniformity, law of noncontradiction, and others. In fact, it was Aristotle who claimed that it was the mark of an uneducated person not to realize that there must be certain first principles of reality such as the foundational law of noncontradiction (Aristotle, Vol. 7, 525).

In our next post, we will discuss the first principles of being, which are properties of reality and through which we come to understand what is. The first principles of reality are both ontological and epistemic in nature.

1Hallucination is pathological. When the mind is functioning correctly, perception is not pathological, it is normative. When determining between reality and hallucination, external objective existence is assumed.

2Self-evident truths, or first principles, are often intuitive but they can become explicit, usually through education. They are impossible to deny because they must be assumed in any attempt to deny them.

Works Cited

Aquinas, Thomas. The Summa Theologica: 1. Great Books of the Western World. Vol. 17. Encyclopedia Britannica, Inc., 1999.

Aristotle. The Works of Aristotle: 1. Great Books of the Western World. Vol. 7. Encyclopedia Britannica, Inc., 1999.

Berkeley, George. The Principles of Human Knowledge. Great Books of the Western World. Vol. 55. Encyclopedia Britannica, Inc., 1999.

Whitehead, Alfred North. Science and the Modern World. Great Books of the Western World. Vol. 55. Encyclopedia Britannica, Inc., 1999.