Can We Know Reality And How Can We Know

A Lecture on the Idealism of Bishop Berkeley vs. John Locke’s Empiricism

A perennial debate is joined by philosophers regarding exactly what comprises the content of our minds.  Is that content reflective of an encounter with reality that grants us knowledge of things in themselves as they really are or are our ideas only things that represent reality to us but are one remove away from the world that (we assume) is distinct from our minds and, therefore, is not truly knowable in itself by our minds.  Multiple lines of philosophical analysis and reasoning run through the nexus of this question, far too many to answer in this short essay.  It must suffice, therefore, for us to simply acknowledge that there are enormously important issues at stake regarding the status of scientific theories, moral values, and even religious truths.  While not addressing all of these concerns in this essay, I do want to present a very intriguing perspective on the questions of what we know and how we can be certain that what we know is real and true, namely the fascinating thoughts of Bishop George Berkeley on the ultimate realism of our ideas.  Discussing this question is not of mere historical interest, given that in the contemporary world we have an evidenced in cultural debates a deep sense of skepticism by many persons – academic scholars and “normal” people.  In fact, in many of our institutions of higher education the quest to understand reality has been abandoned as hopeless because of the purported influences that make us incapable of having any sense of objective knowledge.  That quest has been replaced by the inculcation of values and perspectives that borders on propagandistic indoctrination. 

I have chosen to look at Berkeley’s engagement with the epistemology of John Locke and the ontological commitments that the latter had to make based of his epistemological presuppositions.  This choice is made not only because it is an interesting historical and philosophical debate, but because in an important sense Locke’s empiricism represents the beginning of the Anglo-American philosophical tradition’s affianced relationship with skepticism and pragmatism.  I describe it is an engagement, rather than a marriage, because the Anglo-American tradition has never fully “married” itself to skepticism, although it has certainly seriously courted in – sometimes exclusively – for a long while.  One can trace the trajectory from Locke, to Hume, to Kant, to Nietzche and Existentialism, to Logical Postivism and Pragmatism – and perhaps even to so-called Post-modernism — quite readily.  As a way to introduce you to the epistemological questions and problems that are part of the “skeptical” default starting point for so much of contemporary philosophy, I shall examine the debate that raged during a seminal era of modern philosophy – the beginnings of Empiricism – before  it was fully developed.  Berkeley’s Three Dialogues are representative of his thought regarding the ontological primacy of the non-material reality of Mind and Ideas over the material world, and therefore (in his terms) the realism inherent to our knowledge.  Looking at this treatise, we can outline Berkeley’s ontology as it emerges from his epistemology in interaction with the Lockean categories he inherited as the starting point for the discussion.

In response to what he considered the skeptical implications of the empiricist philosophy of his day – of which Locke is the seminal figure – George Berkeley developed an Idealist conceptual framework for Empiricism as a philosophical school of thought.  He argued that our ideas themselves must have primacy in our ontological theories, rather than some occult “primary substance” that Locke posited as the substratum that — while unobservable and therefore unknowable — is nonetheless assumed as the “reality” that produces in us all impressions and thoughts. (A world unknowable in itself, but necessary to presume.)  In contradistinction, Berkeley argued for the proposition that material objects must be understood to be “things” whose only existence is in the mind, because there is no other place they can be known.  Their ontological status, in other words, was purely ideal.  It should be emphasized at the outset that by asserting this claim and defining it, Berkeley was not – by his own account – denying reality to the “material” objects in our minds.  He conceived, rather, that his idealistic approach to the existence of material reality would undercut the inherent skepticism that was a by-product of the empiricism of people such as Locke.  He was convinced that his theory would, instead, provide philosophy with a ground for certainty of the knowledge of things as they really are, because the only things that there are exist only in our minds as the ideas we have of them.  This kind of confidence, he believed, was impossible by Locke’s theory of a material substance underlying things which we perceive, but which we can never know, since we never have any ideas of sensation of this fundamental substance itself.  It can only be a supposition.    

Central to Locke’s empiricism was a distinction he attempted to draw between the primary qualities of things and the secondary qualities of things.  And it was, among other things, this distinction which Berkeley was convinced provided him with ammunition to refute Locke’s empiricism theory of knowledge and, thereby, open the way for a new theory that would defeat skepticism.  Berkeley builds his refutation of Locke’s epistemology and ontology on a discrepancy he thought existed in Locke’s theory of the distinction between the primary qualities of substance itself and the secondary qualities that we experience in our sensory apprehension of the impressions made on us by this substance.  These secondary qualities are what are posited regarding the nature of substance in relationship to our understanding as we experience it.  

  Berkeley seems to assume in this treatise that Locke’s theory of “secondary qualities” actually belies a serious ontological problem for Locke, if one analyzes his epistemology carefully.  This assumption by the bishop, however, is only partially warranted, and therefore only partially helpful for Berkeley in his attack on Locke’s theory and his own attempts to build an alternative Idealist theory of “material” reality.  While refuting Locke was important in the historical context to provide a foundation for Idealism as Berkeley conceives it, Berkeley offer some positive arguments for his position – that  material objects exist only in the minds of the perceivers – which are independent of his refutation of Locke’s theory of “qualities.” Upon examination, however, it is not clear that Berkeley presents Locke’s actual theory precisely and accurately.  So, before we look at Berkeley’s presentation of his interlocutor’s doctrine on this matter, we should briefly outline Locke’s own concepts for fairness and in order to better assess Berkeley’s own position.

Secondary qualities are described, according to Locke in The Essay on Human Understanding, as “qualities” of Substance (reality outside our minds) that are not essential aspects of Substance; rather they exist in our mental awareness.  However, these secondary qualities are not things that exist only in the minds of those who perceive them in the sense that the mind is the sole source of their presence in our understanding.  They are most completely understood by Locke to be the powers that material objects, as part of the Substance we encounter, have inherent to their nature in relationship to our sensory capabilities.  This means, therefore, that relative to human beings as perceivers they produce certain sensations in us as an aspect of their essential existence (relative to us).  Examples of such secondary qualities would be “color,” “taste,” “heat and cold,” etc.  For instance, the color red is not literally “in” the rose that I see in the flower garden at my house, but the rose that I see in the flower garden has – as part of that which makes it what it is – a power of producing, when it acts upon my human sense of sight, the sensation of redness along with the other sensation it produces in my senses via its other secondary qualities, as well as its primary qualities.  The important point is that qua secondary quality the redness I see in the rose is “in” the rose itself, but that redness, of which I have a sensation and therefore have an idea, is not an aspect of the rose itself, but is a power “inherent” to the substance of the rose that affects my senses in a certain way.  To this extent, Locke is not establishing an original notion, because Descartes seems to have thought this way, and Democritus in ancient Greece held a similar notion regarding the way that atoms of one thing cause a reaction in the atoms that comprise our sense organs.  

Regarding the sensation of red and the idea of that sensation, Locke was clear.  The idea of the sensation of seeing red that I have is only in my mind.  Redness is real in my mind, because it is produced via a particular power of the thing that I call a rose in relation to my senses.  Absent a human perceiver, the redness is not “present” in the rose, but it is nonetheless a real sensation of redness.  For that matter, one might say that even the “roseness” of the rose is produced in my sensory experience in the same way as the redness.  Berkeley was correct, therefore, in his apparent interpretation of Locke on secondary qualities as existing as ideas of things only in our minds.  That is the “place” –and the only “place” –where the red of the rose is actually “located”, i.e., in the realm of ideas.  Just as the pain I feel if I prick my finger on the thorn of the rose stem is in me and not the rose, the color I see (as well as the fragrance I enjoy) do not exist in the matter that comprises the rose, but are only in my perception of them.  However, what Berkeley seems to have missed regarding Locke’s conception of secondary qualities is that the power to cause red to appear to our minds is, in the final analysis, some kind of essential feature of the nature of the substance itself relative to human knowers as it acts upon our senses, and thereby produces ideas of sensation in our minds.  

Emphasizing (or perhaps seeing only) the aspect of Locke’s doctrine of secondary qualities in which their reality qua actual qualities that we experience is dependent upon our minds’ encounters, Berkeley thought he had found a chink in Locke’s epistemological armor.  The Bishop reasoned that if secondary qualities only exist in the mind of the perceiver then Locke could not defend his notion of primary qualities as objectively true of Substance and substances.  Berkeley concluded this because, in his assessment, even the qualities or attributes that Locke listed as primary in regard to substance, namely extension, motion, figure, and number, would seem to be as mind dependent as the so-called secondary qualities.  To make Berkeley’s thinking more obvious, compare the sensation of color (which is a secondary quality by Locke’s standards) we receive from an object by its powers to affect our senses in a particular way.  Reflecting on how it varies according to the light in which we see it, the actual color we might predicate of a material object is dependent upon the mental images that we have as an idea of the color (what hue might the “red” be).  In a similar fashion, Berkeley reasoned, the primary qualities that Locke had predicated of substance(s) — extension, motion, figure, and number — in some important ways vary according to the perspective from which we view these things.  In other words, even these so-called objective primary qualities that are purported non-relative to our knowing differ in our minds according to the way that our minds receive the impression of them.  For example, the very same object might appear round or oval, singular or multiple, moving or stationary as we have sensation of them under differing states of experience.  How could Locke defend his claim, therefore, that the primary qualities of objects we perceive are really “in” them.

Berkeley claims these kinds of observations compel us to reject the idea that primary qualities are any different from the understanding he had of Locke’s views on secondary qualities.  The “reality” of primary qualities, therefore, is just as dependent upon the perceiver as secondary qualities.  Thus, Berkeley contends that the only consistent position to hold is that neither primary qualities nor secondary qualities “exist” as aspects of Substance and substance in an extra-mental in the purported material world of reality.  Both are mind-dependent and, therefore, immaterial essences only.  The true esse of their being is percipi.  (The substantial being of these things is only found in their being perceived by way of all of the “qualities.”)  Hence, for Berkeley epistemological modesty demands that we refrain from posting the existence of any type of qualities “in” things that are presumed to have an extra-mental reality.  So far as we can know, the things that we perceive only exist as we are perceiving them; we cannot “know” anything about the primary qualities of things that we do not experience in the ideas of sense (to use Locke’s concept) in our minds.  

For Berkeley, Locke’s theory is not only inconsistent in its treatment of ideas of sensation, but it is also unnecessary.  It posits things as existing in themselves, when in truth what we can know of things is dependent upon our ideas of them alone.  Thus, for Berkeley, Locke’s theory is unintelligible, as well.  When Hylas attempts to defend the idea of substance and of things which exist unknown as they really are but which can affect us via primary, as well as, secondary qualities, Philonous asks him to define what he is talking about.  Such unintelligibility is, in Berkeley’s mind, evidence both of the uselessness of Locke’s epistemology and its utter falseness.  

Berkeley’s critique of Locke’s theory of secondary qualities, while not quite an accurate assessment of Locke’s views, is not the only argument that Berkeley thinks he can put forth to refute the claim that material really exists independent of the mind.  He also thinks that his arguments against the possibility of abstract or general ideas favors his refutation of a material reality that is non-mentally dependent, therefore Idealist and non-material.  He argues that we can never form general ideas about the world from the particular notions and experiences we have in our minds, because we can never conceive of any idea that is not itself a particular.  For example, we cannot, Berkeley claims, think of the general idea of a triangle, because whenever we attempt this, we have in mind a particular triangular shape. What we have always are particular ideas, never general or universal sensory conceptions.  (It must be admitted here that Berkeley seems to be thinking of “ideas” as mental representations that are like pictures or some such.  For a claim could be made that we do have the idea of a triangularity in some definitional sense, without envisioning a particular triangle with a specific shape and size and positioning.)  Nonetheless, this rejection of the notion of abstract ideas as definitional universal concepts provides Berkeley with an argument that is independent of his treatment of primary and secondary qualities in Locke’s scheme.  He even thinks that one of the mistakes that empiricists such as Locke make is to allow for general idea in the first place.  This notion enables them to deceive themselves into thinking they can form an idea of material reality that is abstract, formless, and void of all features.  But when one recognizes, according to Berkeley, that all our ideas are inherently particular the possibility of such abstraction disappears as an intellectual possibility.  

This claim – that all our ideas are of particulars – is related to another argument of Berkeley’s in favor of the ontological immateriality of Reality as we perceive It via the objects of our ideas. All we are immediately aware of are ideas of “external” and “internal” perception, according to Berkeley.  Since this is his conclusion, therefore, he asks whence comes the idea of “matter” (material Substance, in Locke’s theory) as something “we know not what”.  Hume seems to follow Berkeley on this point when he asks what “impression” we have of material substance as something beyond or behind our immediate simple ideas of impressions.  For Berkeley, since all we are aware of are the phenomena that are in our minds, and we have no way of speaking about any other sorts of entities in an intelligible manner, the best conclusion to draw is that the “material objects” that we encounter are really and only “in” our minds. Hence, the only reality there is for us is non-material ontologically.  Furthermore, if what we are aware of are our ideas, Berkeley asks on what basis we can possibility clam that our ideas are “like” the objects they represent to us, if our ideas are non-material and the objects are supposedly material.  An idea is sui generis.  An idea can only be like an idea.  Thus, it is again unintelligible to claim that our ideas represent to us material reality as an ontological fact.  

A final argument that Berkeley utilizes to defend the idea that “material objects” exist only – but really do exist – as ideas involves the existence of the perceiver.  There are, indubitably, sensations and acts of reflection upon our sensations; and there are obviously acts of desiring, loving, willing, etc.  These things have to exist somewhere as some kind of ontological reality.  There must be some underlying substance in which they find expression, for Berkeley, since it is incomprehensible to speak of them otherwise. He assumes that the shared world of mental ideas we experience has to have an objective existence beyond each finite mind, otherwise we could not account for a shared world of experience.  Where would this be, however?   Furthermore, each of us has an immediate awareness in our encounter with the ideas in our minds that we as perceivers are real in existence.  Therefore, if we exist, we must exist as immaterial substances (spirits or minds), in a Cartesian sense.  Thus, since the objects of our sensations exist only “in” us and we are essentially minds, therefore, they depend upon us and are also immaterial and ideal.  Beyond this conclusion, Berkeley reckons that the only way to make sense of our experience of ourselves as sharing a world of ideas about which we can speak together with others is to conclude that the ontological source of all Ideas, which each and all of us experience as discrete non-material entities, must be an immaterial Mind over all that perceives all and each – God.  So, far from Berkeley’s Idealism producing skepticism about the Divine, it is – in his estimation – an important philosophical, even apologetic, defense of the necessity of God.

At the outset I observed that Berkeley’s intent was not, Hume’s claim notwithstanding, to produce skepticism about the reality of the phenomena we experience as material objects, but to counteract it.  Whether or not he does that is open to question.  However, in the final analysis, he claims to Hylas in Three Dialogues through the voice of his protagonist that his theory does not disturb the reality of things, because they really do exist and exist just as we encounter them, and we can be certain of that.  We need to learn how to judge between our ideas so as to discern those things that qua ideas are true objects, fanciful objects and false objects.  However, the world of our experience, Berkeley contended is, nonetheless, real; and it exists just as we encounter it.  Things like cause and effect are real features, not mere associations, as Hume argued.  We can know something of the nature of reality, not merely our “impressions” and the ideas that our minds form out of those impressions, as the great Scottish antagonist (Hume) or the English father of Empiricism (Locke) would have it.  The good bishop was convinced that his idealism did far more justice to the nature of “material objects,” and was in the final analysis more coherent, offering a much cleaner ontology than the alternative an implied dualism in Locke’s theories.  It overcame the threats to knowledge that the occult Substance behind all our ideas upon which Locke tried to ground reality and, later, Hume assumed and simply shipwrecked epistemology and philosophy, not to mention morals and religion.

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Cover photo by Greg Rakozy on Unsplash

Steve Blakemore, Ph.D
Steve Blakemore, Ph.D
Dr. Blakemore is President of the Board at JCW Center and the Professor of Christian Thought at Wesley Biblical Seminary.