The Anglo-Irish philosopher George Berkeley once said “Esse est percipi,” which means “to be is to be perceived.” According to Berkeley, only minds and ideas exist; matter does not exist. He discusses this theory, which will later be referred to as subjective idealism, in his treatise titled, The Principles of Human Knowledge. In this video, we will explore Berkeley’s radical ontology, which, if accepted, resolves many philosophical paradoxes that have haunted mankind from time immemorial.
Berkeley begins the first part of his Treatise by attacking the notion of material substances. He asserts that all bodies are merely ideas. For example, we perceive a brown, four-legged table in the middle of a dining room. The qualities of the table – such as its brownness, its size, its shape, its number of legs, etc. – are ideas that only exist within the mind. The character Morpheus, in the 1999 film The Matrix, explains Berkeley’s argument very well in the following quote: “What is real? How do you define ‘real’? If you’re talking about what you can feel, what you can smell, what you can taste and see, then ‘real’ is simply electrical signals interpreted by your brain.”
Even if we grant that physical bodies exist outside of our minds, Berkeley concludes that we are incapable of knowing that such bodies exist. To illustrate this, let’s consider dreams. While dreaming, we see, hear, smell, taste, and feel external objects that are not actually there. If we perceive objects that are not actually there while we dream, then it follows that our sensations while awake are not necessarily produced by external physical objects. In that case, what produces the sensations we have of mountains, rivers, trees, etc., if there are no external bodies?
Berkeley answers this question by investigating the nature of the mind. He asserts that the mind can either actively create ideas, or passively perceive ideas. Thus, we can choose to recall past memories to our mind, dismiss them, and recall others. But when we open our eyes and view the world, we cannot choose to see or not see the brown, four-legged table in our dining room. At that moment, our mind passively perceives ideas. Because Berkeley claims that there are no physical bodies, he concludes that there must be another Spirit or Mind that produces the idea of the table that we perceive.
Being the Bishop of the Church of Ireland, Berkeley naturally identifies this supreme Spirit as the Christian God. Because God is infinitely wise, good, and powerful, He is able to produce Ideas that are more real than those that we are able to call forth in our own minds. Thus, Berkeley accounts for the difference between reality and our dreams, hallucinations, and thoughts. Reality, which is produced by God, is more regular, consistent, and vivid than the Ideas produced by us while dreaming, hallucinating, or reminiscing.
Berkeley believed that his theory had several beneficial consequences. It resolved many philosophical paradoxes. For example, if Berkeley is correct that only minds and ideas exist, then the questions of whether material bodies can think, whether matter is infinitely divisible, and whether material bodies and immaterial souls can interact are questions that must be dismissed as nonsense because matter does not exist.
Although Berkeley’s immaterialism is initially repugnant to common sense, after some reflection, one finds that his argument is more resilient than first anticipated. At the very least, Berkeley’s treatise deserves serious consideration rather than rash disregard. And I highly recommend this treatise to both believers and non-believers. One party will discover a strong ally, and the other party will discover a worthy opponent.