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 sensation 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.
“PHILOSOPHY being nothing else but the study of Wisdom and Truth, it may with reason be expected, that those who have spent most Time and Pains in it should enjoy a greater calm and serenity of Mind, a greater clearness and evidence of Knowledge, and be less disturbed with Doubts and Difficulties than other Men. Yet so it is we see the Illiterate Bulk of Mankind that walk the High-road of plain, common Sense, and are governed by the Dictates of Nature, for the most part easy and undisturbed. To them nothing that’s familiar appears unaccountable or difficult to comprehend. They complain not of any want of Evidence in their Senses, and are out of all danger of becoming Sceptics. But no sooner do we depart from Sense and Instinct to follow the Light of a Superior Principle, to reason, meditate, and reflect on the Nature of Things, but a thousand Scruples spring up in our Minds, concerning those Things which before we seemed fully to comprehend. Prejudices and Errors of Sense do from all Parts discover themselves to our view; and endeavouring to correct these by Reason we are insensibly drawn into uncouth Paradoxes, Difficulties, and Inconsistencies, which multiply and grow upon us as we advance in Speculation; till at length, having wander’d through many intricate Mazes, we find our selves just where we were, or, which is worse, sit down in a forlorn Scepticism.”
“The cause of this is thought to be the obscurity of things, or the natural weakness and imperfection of our understandings. Upon the whole, I am inclined to think that the far greater part, if not all, of those difficulties which have hitherto amused philosophers, and blocked up the way to knowledge, are entirely owing to ourselves – that we have first raised a dust and then complain we cannot see.”
“What more easy than for anyone to look a little into his own Thoughts, and there try whether he has, or can attain to have, an Idea that shall correspond with the description that is here given of the general Idea of a Triangle, which is, neither Oblique, nor Rectangle, Equilateral, Equicrural, nor Scalenon, but all and none of these at once? If any Man has the Faculty of framing in his Mind such an Idea of a Triangle as is here described, it is in vain to pretend to dispute him out of it, nor would I go about it.”
“That neither our thoughts, nor passions, nor ideas formed by the imagination, exist WITHOUT the mind, is what EVERYBODY WILL ALLOW. The table I write on I say exists, that is, I see and feel it; and if I were out of my study I should say it existed – meaning thereby that if I was in my study I might perceive it, or that some other spirit actually does perceive it. This is all that I can understand by these and the like expressions. Their ESSE is PERCIPI, nor is it possible they should have any existence out of the minds or thinking things which perceive them.”
“What are the forementioned Objects but the things we perceive by Sense, and what do we perceive besides our own Ideas or Sensations?”
“The Things we see and feel, what are they but so many Sensations, Notions, Ideas or Impressions on the Sense; and is it possible to separate, even in thought, any of these from Perception?”
“But though it were possible that solid, figured, moveable Substances may exist without the Mind, corresponding to the Ideas we have of Bodies, yet how is it possible for us to know this? Either we must know it by Sense, or by Reason. As for our Senses, by them we have the Knowledge only of our Sensations, Ideas, or those things that are immediately perceived by Sense, call them what you will: But they do not inform us that things exist without the Mind, or unperceived, like to those which are perceived. This the Materialists themselves acknowledge. It remains therefore that if we have any Knowledge at all of external Things, it must be by Reason, inferring their Existence from what is immediately perceived by Sense. But what reason can induce us to believe the Existence of Bodies without the Mind, from what we perceive, since the very Patrons of Matter themselves do not pretend, there is any necessary Connexion betwixt them and our Ideas? I say it is granted on all hands (and what happens in Dreams, Phrensies, and the like, puts it beyond dispute) that it is possible we might be affected with all the Ideas we have now, though no Bodies existed without, resembling them. Hence it is evident the Supposition of external Bodies is not necessary for the producing our Ideas: Since it is granted they are produced sometimes, and might possibly be produced always in the same Order we see them in at present, without their Concurrence.”
“Though we give the Materialists their external Bodies, they by their own confession are never the nearer knowing how our Ideas are produced: Since they own themselves unable to comprehend in what manner Body can act upon Spirit, or how it is possible it should imprint any Idea in the Mind.”
“But say you, surely there is nothing easier than to imagine Trees, for instance, in a Park, or Books existing in a Closet, and no Body by to perceive them. I answer, you may so, there is no difficulty in it: But what is all this, I beseech you, more than framing in your Mind certain Ideas which you call Books and Trees, and the same time omitting to frame the Idea of any one that may perceive them? But do not you your self perceive or think of them all the while?”
“We perceive a continual Succession of Ideas, some are anew excited, others are changed or totally disappear. There is therefore some Cause of these Ideas whereon they depend, and which produces and changes them. That this Cause cannot be any Quality or Idea or Combination of Ideas, is clear from the preceding Section. It must therefore be a Substance; but it has been shewn that there is no corporeal or material Substance: It remains therefore that the Cause of Ideas is an incorporeal active Substance or Spirit.”
“A Spirit is one simple, undivided, active Being: as it perceives Ideas, it is called the Understanding, and as it produces or otherwise operates about them, it is called the Will. The Words Will, Soul, Spirit, do not stand for different Ideas, or in truth, for any Idea at all, but for something which is very different from Ideas, and which being an Agent cannot be like unto, or represented by, any Idea whatsoever. Though it must be owned at the same time, that we have some Notion of Soul, Spirit, and the Operations of the Mind, such as Willing, Loving, Hating, in as much as we know or understand the meaning of those Words.”
“I find I can excite Ideas in my Mind at pleasure, and vary and shift the Scene as oft as I think fit. It is no more than Willing, and straightway this or that Idea arises in my Fancy: And by the same Power it is obliterated, and makes way for another. This making and unmaking of Ideas doth very properly denominate the Mind active. But whatever Power I may have over my own Thoughts, I find the Ideas actually perceived by Sense have not a like Dependence on my Will. When in broad Day-light I open my Eyes, it is not in my Power to choose whether I shall see or no, or to determine what particular Objects shall present themselves to my View; and so likewise as to the Hearing and other Senses, the Ideas imprinted on them are not Creatures of my Will. There is therefore some other Will or Spirit that produces them.”
In the Introduction of his Treatise, Berkeley discredits the Platonic notion of abstract general ideas. He asserts that one cannot conceive of abstract ideas. For example, it is impossible to conceive of the abstract idea of a triangle; the abstract idea of a triangle is one which is neither acute, nor obtuse, nor right, but all of these and none of these at once. “If any Man has the Faculty of framing in his Mind such an Idea of a Triangle as is here described, it is in vain to pretend to dispute him out of it, nor would I go about it.”