Philosophy of the Modern Era

Berkeley

George Berkeley (1685—1753) gained prominence in philosophy through his denial of the existence of matter—a denial that he supported with a series of ingenious arguments. He asserted that material objects exist only when perceived. In response to the objection that a tree, for instance, would cease to exist if no one were looking at it, he countered that God perceives everything at all times; without the existence of God, what we consider material objects would have a sporadic existence, abruptly coming into being only when we looked at them. However, it is due to God's perception that trees, rocks, and stones exist as consistently as common sense suggests. This, in his view, serves as a compelling argument for the existence of God. Ronald Knox's limerick encapsulates Berkeley's theory of material objects:

There once was a young man who said,
“It must be extremely amusing to God,
If He discovers that this tree
Continues to be,
Even when no one’s in the yard.”
Response:
“Dear Sir,
Your surprise is quite strange:
I’m always in the yard,
And that’s why the tree
Will exist,
Observed
By your humble servant God.”

Berkeley was Irish and became a tutor at Trinity College, Dublin, at the age of 22. He was introduced to Swift’s court, and Vanessa Swift bequeathed him half her fortune. He devised a plan for a college in the Bermuda Islands, for which he traveled to America, but after spending three years on Rhode Island (1728—1731), he returned home and abandoned this project. He is known for the famous phrase: “The development of the empire is directed westward,” which led to a town in California being named after him. In 1743, he became a bishop in Cloyne. In the later years of his life, he turned away from philosophy due to his fascination with tar tincture, which he attributed with miraculous medicinal properties. He described the tar tincture as: “It brings cheerfulness, but does not intoxicate,” a characterization that echoes Cowper's later description of the effects of tea.

All his best works were written while he was still quite young: "An Essay Towards a New Theory of Vision" in 1709, "A Treatise Concerning the Principles of Human Knowledge" in 1710, and "Three Dialogues between Hylas and Philonous" in 1713. His works produced after the age of 28 are less significant. He is an appealing writer, possessing a graceful style. His arguments against matter are most convincingly articulated in "Dialogues between Hylas and Philonous." From these dialogues, I intend to examine only the first and the beginning of the second, as everything said thereafter seems to me less important. In the section of the work that I will discuss, Berkeley presents effective arguments in support of a significant conclusion, albeit not quite the conclusion he believes he is proving. He thinks he provides evidence for the reality of spirituality, but what he actually demonstrates is that we perceive qualities rather than things, and that qualities are relative to the perceiving subject.

I will begin with a non-critical exposition of what I find important in "Three Dialogues," then I will proceed to a critical analysis, and finally, I will express my views on the issues raised as I conceive them.

There are two characters in "Three Dialogues": Hylas, who defends the commonly accepted views of the scientifically educated man of that time, and Philonous, who represents Berkeley himself.

After some friendly remarks, Hylas exclaims that strange rumors have reached him regarding Philonous's views, specifically that he does not believe in material substance. “Could there be anything,” he exclaims, “more fantastic, more contrary to common sense, or a more evident example of skepticism than to think that matter does not exist?” Philonous replies that he does not deny the reality of sensible things, meaning those directly perceived by the senses, but that we do not see the causes of colors or hear the causes of sounds. Both agree that the senses do not provide conclusions. Philonous points out that through sight we perceive only light, color, and shape; through hearing, only sounds, and so forth. Therefore, beyond sensible qualities, there exists nothing sensible, and sensible things are nothing more than sensible qualities or combinations of sensible qualities.

Philonus then attempts to prove the position that “the reality of sensible things consists in being perceived,” in opposition to Hylas's view that “to exist is one thing, and to be perceived is another.” He supports the thesis that sensory data are mental by thoroughly examining various senses. He begins this examination with a discussion of warmth and cold. Excessive heat, he argues, is suffering, and suffering must exist in the mind that perceives it. Therefore, warmth is a mental phenomenon. A similar argument applies to cold. This is reinforced by the famous argument regarding warm water. When one hand is hot and the other cold, and both are placed in warm water, one will feel cold while the other feels warmth; yet, the water cannot simultaneously be warm and cold. This disarms Hylas, who admits that “warmth and cold are merely sensations that exist in our souls.” However, he optimistically points out that other sensory qualities remain.

Next, Philonous analyzes sensory perceptions. He asserts that sweetness is pleasure, while bitterness is suffering, and that pleasure and suffering are mental phenomena. Similar arguments apply to smells, which are either pleasant or unpleasant.

Gilas makes a vigorous effort to defend the objective existence of sound against Philonous’s critique, claiming it to be a vibration of air; this is substantiated by the fact that sound does not exist in a vacuum. He contends that we must "distinguish between sound as it is perceived by us and sound as it exists in itself, or between the sound we directly perceive and the sound that exists outside of us." Philonous counters that what Gilas refers to as "actual" sound, being a movement, may be visible or tangible, but certainly cannot be heard; therefore, it is not the sound we know through perception. To this, Gilas now concedes that "sounds also do not have actual being outside of the mind."

They then move on to an analysis of colors, where Gilas begins with confidence: "Forgive me; the matter of colors is entirely different. Could anything be clearer than our seeing them in objects?" He asserts that substances existing outside the mind possess colors that we see. However, Philonous finds no difficulty in refuting this view. He starts by considering clouds at sunset, which exhibit reddish and golden hues, pointing out that a cloud, when you are close to it, has no such color. He then discusses the differences in objects revealed under a microscope and the yellowness that afflicts everything for someone suffering from jaundice. He posits that very small insects must be capable of seeing objects smaller than we can. In response, Gilas argues that color resides not in objects, but in light; he claims that light is a subtle, flowing substance. Philonous, as with sound, points out that according to Gilas, "actual" colors are something different from the red and blue we perceive, and that this cannot be explained as such.

After this, Gilas concedes on the issue of the nature of all secondary qualities in favor of Philonous but continues to assert that primary qualities, especially figure and motion, belong to external, non-thinking substances. Philonous replies that things appear large when we are close to them and small when we are far from them, and that motion can seem fast to one person and slow to another.

Gilas then attempts to adopt a new strategy in his dispute with Philonous. He admits that he has made a mistake by failing to distinguish the object from the sensation; he concedes that the act of perception is mental but insists that what is perceived, such as color, "has actual existence outside of the mind—in some non-thinking substance." To this, Philonous responds: "For any immediate object of the senses (that is, any representation or combination of them) to exist in a non-thinking substance or outside any mind—this entails an obvious contradiction." It should be noted that from this point onward, the argument is no longer empirical but becomes logical. A few pages later, Philonous states: "Everything that is directly perceived is an idea—and can an idea exist outside the mind?"

After the metaphysical dispute regarding substance, Gilas returns to the discussion of visual sensations, presenting the argument that he sees things at a distance. Philonous replies that this is equally true for things seen in dreams, which everyone considers to be mental phenomena; furthermore, that distance is not perceived visually but is suggested as a result of experience, and that for a person born blind who sees for the first time, visible objects do not seem distant.

At the beginning of the second dialogue, Gilas argues that the causes of sensations are certain traces in the brain, but Philonous counters that "the brain, being a sensory thing, exists only in the mind."

The remainder of the dialogues is less interesting, and there is no need to explore it further.

Now, let us embark on a critical analysis of Berkeley’s assertions.

Berkeley’s argument consists of two parts. On one hand, he demonstrates that we do not perceive material things but only colors, sounds, and so forth, which are "mental" or "existing in the mind." His justifications for the first assertion are exceedingly convincing; however, regarding the second, he lacks any definition of the term "mental." In fact, he relies on the widely held view that all things must be either material or mental, that nothing can be both simultaneously.

When he claims that we perceive qualities, not "things" or "material substances," and that there is no basis for believing that different qualities, which common sense regards as belonging to one "thing," pertain to a substance distinct from each of them and from all of them, his reasoning can be accepted. But when he continues to assert that sensory qualities, including primary qualities, are mental, his arguments vary in nature and degree of evidence. Some demonstrate logical necessity, while others are more empirical. Let us first consider the former.

Philonous states: "All that is directly perceived is an idea—and can an idea exist outside the mind?" A lengthy discussion about the word "idea" would be required. If one were to assume that thought and perception consist of a relationship between subject and object, it would then be possible to equate the mind with the subject and argue that there is nothing "in" the mind, but rather objects "before" it. Berkeley examines the perspective that we must distinguish the act of perception from the perceived object, with the former being mental while the latter is not. His argument against this perspective is unclear, and this is inevitable, for one who believes in mental substance, as Berkeley does, lacks an effective means to refute it. He states: "For any immediate object of sense to exist in a non-thinking substance or outside all minds—this entails an obvious contradiction." Here, there is an error akin to the following: "There is no nephew without an uncle; thus, if A is a nephew, it is logically inevitable that A has an uncle." Certainly, this is logically necessary on the condition that A is a nephew, but not as something that can be discerned by analyzing A itself. Therefore, if something is an object of sensation, it must relate to some mind; however, this does not imply that the same thing would not exist were it not an object of sensation.

To some extent, a similar error pertains to the imagined. Gilas asserts that he can conceive of a house that no one perceives and which exists in no one's mind. Philonus counters that whatever Gilas imagines resides in his mind, making the proposed house ultimately a mental construct. Gilas might respond, "I do not mean to imply that I have in mind an image of a house when I say I can conceive of a house that no one perceives; what I truly wish to convey is that I can comprehend the proposition: 'There exists a house that no one perceives,' or better yet: 'There exists a house that neither anyone perceives nor imagines.' This proposition is entirely composed of intelligible words, and the relationship between the words is sound. Whether the assertion is true or false, I do not know, but I am certain that it cannot be shown to be internally contradictory. A series of very similar assertions can be proven. For instance, the number of possible products of two integers is infinite; hence there exist numbers that no one has ever thought of. Berkeley’s argument, if accepted as valid, would assert that this is impossible."

The fallacy here is widespread. We can use concepts derived from experience to formulate statements about classes, some or all members of which are not derived from experience. Take an entirely mundane concept, say, "cobblestone"; this is an empirical concept derived from perception. However, this does not imply that all cobblestones are perceivable unless we include the fact of perception in our definition of the term "cobblestone." If we do not do so, the concept of an "unperceivable cobblestone" logically poses no objection, despite the fact that it is logically impossible to perceive an example of it.

Schematic representation of the argument might look as follows. Berkeley asserts, "Sensory objects must be perceivable. A is a sensory object. Therefore, A must be perceivable." But if "must" indicates logical necessity, then the argument can only be deemed effective if A is necessarily a sensory object. This argument does not prove that from the properties of A, other than being sensory, one can derive that A is a sensory object. However, it has been demonstrated, for example, that colors, essentially different from those we see, cannot exist while remaining unseen. On physiological grounds, we may assume that this does not happen, but such a basis is empirical; in terms of logic, there are no grounds for denying the presence of colors where there are no eyes or brains.

Now I turn to Berkeley's empirical arguments. First and foremost, the combination of empirical and logical arguments signifies weakness, as the latter, if considered effective, render the former superfluous. If I assert that a square must not be round, I will not refer to the fact that there is not a single round square in any known city. However, since we have rejected the logical arguments, it becomes necessary to examine the empirical arguments accordingly, based on their merits.

The first of the empirical arguments is peculiar: it posits that warmth cannot exist in an object because "the highest and most intense degree of warmth constitutes great suffering," and we cannot suppose that "any non-perceptive thing could experience suffering or pleasure." The term "suffering" carries ambiguity that Berkeley exploits. It may denote the unpleasant nature of a sensation, or it may refer to the sensation that possesses this quality. We say, "a broken leg hurts," without implying that the leg exists in the mind. Similarly, it is possible that warmth causes suffering, and that is all we need to mean when we say: "this is suffering." Therefore, this argument is untenable.

The argument regarding hot and cold hands in warm water would strictly prove only that what we perceive in this experience is not hot or cold but merely more or less so. It requires no demonstration that these perceptions are subjective.

Regarding tastes, the argument of pleasures and pains is reiterated. Sweetness is pleasure, while bitterness is suffering; thus, both pertain to mental phenomena. It is further demonstrated that a thing whose taste is sweet when I am healthy may taste bitter when I am ill. Very similar arguments are made concerning odors: since they are pleasant or unpleasant, "they can only exist in a perceiving substance or in the mind." Berkeley here, as elsewhere, concedes that what is not inherent in matter must be inherent in mental substance and that nothing can be both mental and material simultaneously.

The argument concerning sound is an ad hominem argument. Gilas asserts that "real" sounds are vibrations of air, and Philonus counters that vibrations can only be seen or felt, but not heard; thus, "real" sounds are inaudible. This is hardly a sound argument, as perceptions of vibrations, according to Berkeley, are as subjective as any other perceptions. The vibrations that Gilas requires to prove the objectivity of sound must be imperceptible and unnoticed. Nonetheless, this point holds value insofar as it indicates that sound, as we hear it, cannot be equated with the vibrations of air that physics regards as its cause.

After renouncing secondary qualities, Gilas remains reluctant to abandon primary qualities—such as extension, figure, density, weight, motion, and rest. Naturally, the arguments center around extension and motion. If things possess actual sizes, Philonus argues, then the same object cannot simultaneously have different sizes; yet it appears larger when we are close to it than when we are distant. And if motion is indeed inherent in an object, how is it that the same motion may seem fast to one person and slow to another? I believe such arguments can demonstrate the subjectivity of perceived space. However, this subjectivity is physical: it holds true for a camera as well, and therefore does not prove that form is "mental." In the second dialogue, Philonus summarizes this portion of the discussion in the words: "Except for spirits, all that we know or conceive are our own representations." Of course, he should not have made an exception for spirits, as it is equally impossible to know spirit as it is to know matter. In fact, in both cases, the arguments are nearly identical.

Now let us attempt to establish what positive conclusions we can draw based on the arguments presented by Berkeley.

Things, as we perceive them, are a collection of sensory qualities: for instance, a table consists of its visible shape, hardness, the sound it produces when struck, and its odor (if any). These various qualities are connected in a certain way within experience, leading common sense to regard them as attributes of a single "thing." However, the concept of "thing" or "substance" adds nothing to the perceived qualities and is not necessary. Thus far, we stand on firm ground.

But now we must ask ourselves what we mean by the process of perception. Philonous asserts regarding sensory things that their reality lies in being perceived. Yet he does not clarify what he understands by perception. There exists a theory that he rejects, positing that perception is a connection between the subject and the perceived object. Since he holds that the ego is a substance, he could readily accept this theory; however, he opposes it. For those who deny the notion of a substantial ego, this theory is unacceptable. So what do we mean when we call something perception? Does it imply something beyond that which is stated? Can we reverse Berkeley’s position and instead claim that to be perceived is to be real? In any case, Berkeley considers it logically possible for unperceived things to exist, as he believes that some real entities, namely the substances of spirits, are unperceived. It seems evident that when we say an event is perceived, we mean something greater than its mere occurrence.

What, then, constitutes this greater element? The obvious distinction between a perceived and an unperceived event is that the former can be remembered, while the latter cannot. Are there any other distinctions?

Memory is one of a range of actions more or less characteristic of phenomena we naturally call "mental." These actions are linked to habit. A burned child fears fire, yet a heated poker does not. However, a physiologist, examining habit and related phenomena as characteristics of nervous tissue, need not depart from a physical interpretation of these phenomena. Adhering to the language of physicists, we might say that a phenomenon is "perceived" if it exerts certain effects; in this sense, we might almost say that a river "perceives" rain, by which it becomes deeper, and that a river valley represents the "memory" of past downpours. Habit and memory, when described in the language of physics, are not entirely absent in inanimate matter; the difference in this respect between living and dead matter is merely one of degree.

From this perspective, to say that an event is "perceived" is to state that it exerts certain effects, and there is neither logical nor empirical foundation to suppose that all events exert such effects.

Epistemology offers a different viewpoint. Here, we will not start from a complete scientific theory but from any knowledge that underpins our faith in science. This is precisely what Berkeley does. There is no need to predefine the concept of "perception." The method is roughly as follows: we group assertions that we believe we know without inference and ascertain that most of them must deal with individual events. We define these events as "perceptions." Therefore, perceptions are those events we know without inference, or at least we ascertain through memory that they were once perceived. We are then faced with the question: can we infer from our own perceptions any other events? Here, four perspectives are possible, of which the first three represent varieties of idealism.

1. We may wholly deny the validity of any inferences from my current perceptions and memories to other events. This viewpoint must be upheld by anyone who restricts logical inferences to deduction. Any event and any group of events can logically exist in isolation, and therefore no group of events provides conclusive evidence for the existence of other events. Consequently, if we limit inference to deduction, the known world will be confined to those events in our own biographies that we perceive or have perceived (if memory retains them).
2. The second viewpoint, typically understood as solipsism, allows for certain inferences from my perceptions but only concerning other events in my own biography. For instance, we may adopt the perspective that, at any moment of wakefulness, there are sensory objects of which we are unaware. We see many things without noting that we see them, at least it seems so. Upon closely examining the surroundings where we perceive no movement, we might notice a sequence of diverse objects and ascertain that they were visible before we took note of them; yet before we noticed them, they were not given for the theory of knowledge. This stage of inference from observation is made by everyone without reflection; it is even done by those most eager to avoid extending our knowledge beyond experience.
3. The third viewpoint, seemingly supported by Eddington, asserts that we can make inferences about other events analogous to those in our own experience, and thus we have grounds to believe in the existence, for instance, of colors that we do not see, but others do, in the toothaches felt by others, in the pleasures they experience, and the sufferings they endure, etc. However, we have no right to logically infer events that no one has experienced and that do not form part of any "mind." This viewpoint can be justified on the basis that all inferences about events beyond my observation occur through analogy, and that events no one experiences are insufficiently analogous to my data to warrant similar conclusions.
4. The fourth viewpoint is one of common sense and traditional physics, according to which, in addition to my experience and that of others, there are also events that are no one’s experience, such as the furniture in my bedroom while I sleep and it remains in utter darkness. G.E. Moore once accused idealists of believing that trains have wheels only when they are at stations, on the grounds that passengers cannot see the wheels while they are in the train. Common sense refuses to accept that wheels suddenly appear every time one looks at them, but do not exist when no one observes them. If this viewpoint is scientific, it substantiates conclusions about unperceived events based on causal laws.

At present, I do not intend to choose among these four perspectives. A decision, if it is possible at all, can be made only through a thorough investigation of unproven inferences and the theory of probability. My intent has merely been to point out certain logical errors made by those who have discussed these issues.

Berkeley, as we have observed, posits that there are logical grounds supporting the notion that only minds and mental events can exist. This perspective is similarly upheld by Hegel and his followers on other grounds. I am convinced that this assertion is fundamentally erroneous. A statement such as "there was a time before life existed on Earth," whether true or false, can be dismissed on logical grounds no more than one can refute the proposition that "there are such products of multiplication that no one will ever compute." To be observed or to be an object of perception simply means to exert certain kinds of effects, and there are no logical grounds to presume that all events must have such effects.

However, there exists another argument that, while it does not advocate for idealism as a metaphysical doctrine, asserts it as a practical line of conduct if one acknowledges it to be correct. It is claimed that a statement that cannot be verified is devoid of significance; that verification hinges upon perceptions, and thus a statement regarding anything other than factual or possible perceptions is meaningless. I believe that this view, if strictly interpreted, would confine us to the first of the aforementioned four theories and prevent us from speaking of anything we have not directly observed. If so, this perspective is one that no one can uphold in practice, which is a shortcoming for a theory preached from a practical standpoint. In general, the question of verification and its connection to knowledge is a complex and intricate matter; therefore, I shall set it aside for the moment.

The fourth of the previously mentioned theories, which allows for events that no one perceives, can also be defended only through ineffective arguments. It may be posited that causality is known a priori and that causal laws are impossible unless there exist unperceived events. Conversely, one can argue that causality is not a priori and that all that can be observed in ordinary sequences must relate to perceptions. Regardless of the grounds for believing in the laws of physics, it appears essential to be able to employ the terminology of perception in this context. This assertion may seem strange and complicated; it may lack the fundamental features of integrity that were once expected of physical laws. Nonetheless, it is unlikely to be impossible.

In conclusion, I assert that there exists no a priori objection to any of our four theories. However, it may be claimed that all truth is pragmatic and that, from a pragmatic standpoint, there is no difference among the four theories. If this is true, we may adopt any of them that we prefer, with the distinction between them being merely linguistic. I cannot accept this viewpoint, and this too is a matter for further discussion.

It remains to be asked whether we can ascribe any meaning to the words "mind" and "matter." Everyone knows that "mind" refers to what the idealist believes exists solely as mind, while "matter" pertains to what the materialist similarly believes. I hope the reader also understands that idealists are virtuous while materialists are immoral. Yet perhaps more can be said than this.

My own definition of "matter" may seem unsatisfactory; I would define it as that which satisfies the equations of physics. It is possible that nothing satisfies these equations; if that is the case, then either physics or the concept of "matter" is erroneous. If we deny substance, then "matter" must be a logical construct. Whether any construct can be composed of events that may be partially inferred is a challenging question, yet it is by no means insurmountable.

As for "mind," if substance is rejected, the mind must be some group or structure of events. The grouping of these events must be accomplished through certain connections characteristic of the type of phenomena we term "psychical." We might take memory as a typical example. We could, albeit rather simplistically, define a "psychical" event as one that remembers or is remembered. Thus, the mind to which a given psychical event belongs is a cluster of events linked to that event by chains of recollection that connect it with preceding and subsequent events.

From this perspective, it can be seen that, according to the definition above, both mind and a part of matter represent a collection of events. There is no reason why each event should belong exclusively to one group or the other, nor is there any reason why certain events should not belong to both groups; therefore, some events may be neither mental nor material, while others may embody both characteristics. All of this can only be resolved through detailed empirical observations.