Locke, Berkeley, Hume, Kant, and the Rise of German Idealism
by P.T. Mistlberger
Locke, Berkeley, and Hume
John Locke was born in
1632 in southwest England.
He was an Oxford
graduate and in addition to being generally recognized as one of the great
English empirical philosophers, he was also a medical doctor. His influence was
broad; he is usually credited with being one of the original ‘liberals’, and
his writings on political philosophy were admired by such august figures as
Voltaire and the Founding Fathers of the United States (such as Franklin and
Jefferson). Like Kant, his more mature philosophical writings did not appear
until he was in his late 50s.
Locke followed in the footsteps of the great empiricist Francis Bacon, and was also profoundly influenced by Isaac Newton. Intellectual Europe of the 17th century was awash in the excitement of the birth of empirical science, all based on the general idea that Nature could be understood and explained by the mind, and that further, the mind itself could be understood by the mind. In short, reason was supreme, with the potential of not just devising theories to explain the universe and with creating technologies that could eventually harness the vast powers of Nature itself (to be realized the following century via the Industrial Revolution), but also with the extraordinary capacity to understand its own functioning. With Locke, Western philosophy had entered a new phase: examining, in closely reasoned detail, the workings of the mind itself.
It was in the early
periods of this phase that Locke put forth his most significant philosophical
ideas, first published in 1690 as An
Essay Concerning Human Understanding. Although some of his views were later
refuted quite convincingly, his work remains highly significant because he was
arguably one of the first Western thinkers to begin applying rigorous thought in
a fashion similar to how the great Vedantic and Buddhist sages of the East had
done centuries before—although Locke himself, with no strong introspective
philosophical tradition to fall back on, arrived at only preliminary
understandings on his own.
The essence of his main ideas published in his great Essay can be summarized as all mind-content is dependent on sensory input. As Locke saw it, the mind in its pristine state is nothing but a blank screen, a tabula rasa, a hard drive with nothing on it upon which are written ‘programs’ that contain the ‘code’ received from our senses. Everything we think and call ‘knowledge’ derives ultimately from our sensory input. The data received from our senses becomes memory, and then concepts, and then our various levels of understanding. It is the essence of realism: consciousness ultimately arises from matter, since all our ideas are based on the sense impressions our bodies receive from the material universe. We know nothing without our senses. There are no ‘native ideas’ that somehow exist independent of our sensory experience (thus putting Locke in direct opposition to Descartes), and thus there are no ‘innate principles’ (a serious threat to religion). This does not mean, of course, that we cannot devise elaborate mental constructs, but rather that all reflections, regardless of how complex, ultimately arise from sensory experience.
Locke’s position epitomized the essential creed of the 17th century ‘Enlightenment’ (Age of Reason), which was that all knowledge of ‘things’ was held to be based on sensory experience, and that anything else was meaningless imagination. In other words, we know the world only via the body. Matter is the base of the pyramid, with all intellectual understanding sitting at the top, ‘resting’ on matter. The mind is an emergent property of the brain, nothing more, and relies entirely on the senses of the body to develop ideas about the universe in which it dwells.
Locke elaborated this
position in some detail. He did not claim that no knowledge whatsoever is
possible without sensory input, but allowed that certain forms of knowledge,
such as that derived from mathematics and logical operations, was obtainable.
We do not need to see, hear, touch, taste, or smell in order to grasp that
2+2=4. But such knowledge is isolated, and cannot help us to ‘know’ the world
in any real fashion. For that, according to Locke, we need sensory experience.
Locke took from Descartes (and developed) the concept of two essential types of ideas: the simple and the complex. A simple idea is that which derives from a particular physical sense—such as, the sound of a dog barking. A complex idea is based on a combination of simple ideas—for example, I have seen the dog, it is black in color and of this particular size, and it makes this type of barking sound. The idea is that a simple idea cannot be broken down further, but can be built on. It was from the basis of different types of ideas that Locke proposed we are capable of distinguishing between what he called the primary and secondary qualities of a given object. Primary qualities are those that will be perceived as the same by all people—examples being size and shape. Secondary qualities depend on sensory interpretation, such as smell, sound and color, and will not be experienced as the same by everyone. For example, a color-blind person will not see a red square block the same as a person with normal vision, but both can agree on the exact size of the object. Therefore, the size is a primary quality, and the color a secondary quality. From all this Locke concluded that scientific exactitude was possible, and real knowledge of things could be attained, by analyzing primary qualities. This position has been called ‘representative realism’, because it is based on the idea that our mind represents the world, but does not replicate it.
The Irish philosopher George Berkeley (b. 1685, later Bishop Berkeley), was five years old when Locke published his Essay; unlike Locke his important publications were produced at a young age. In 1710, at just twenty-five, he published his A Treatise Concerning the Principles of Human Knowledge, in which he put forth his opposition to some of the essential tenets of Locke’s ideas.Berkeley’s main argument was that Locke had erred by not going far enough, by not following his reasoning to its logical conclusion. Berkeley reasoned that there was no true difference between so-called primary and secondary qualities, in that both were experienced as thoughts in the mind. From this position, Berkeley claimed that all we can really know for certain are our ideas about things—we cannot conclude, with absolute certainty, that our thoughts correctly represent any ‘thing’ in the world. All we can conclude for certain is that we are experiencing these thoughts. We cannot escape the reality that our experience of anything and everything is via our mind, and therefore, all we can assume truthfully is that we know reality via our mind.
Berkeley was, however, a Christian, and so like the old Scholastics such as Thomas Aquinas, he sought to flesh out his views in such as way as to keep God at the center of all. His way of reasoning this out was clever. As mentioned, he argued that the so-called material universe is known to us only via our perceptions and ideas of it. In sharp denial of Descartes and Locke, he maintained that material reality has no intrinsic existence but is rather only an appearance. This view, however, brings up the classic paradox of idealism: if no one is present to see and hear the tree falling in the forest, did it actually fall? Or, even more simply, if no one is there to perceive the forest, does it actually exist? It might seem, at first glance, that Berkeley’s position must hold that if no one sees and hears the fall of the tree, it never fell; or that if no one is there to perceive the forest and to thus have an idea about the forest, it cannot truly exist. But this seems to be an obvious absurdity. For example, if evolution is essentially correct, there was a time during the history of our planet when there was no consciousness. And yet clearly the planet existed independent of any consciousness to perceive it, otherwise all of life, and ultimately we humans, would have had no planet upon which to evolve in the first place.
Berkeley managed to work out this problem while at the same time preserving the idea of the central existence of God. His solution was simple: all ideas ultimately derive from the mind of God. And thus, the fact that things retain their apparent existence is due to the existence of God’s ideas. More, the very existence of apparent things, independent of an individual consciousness (such as a person) to develop ideas about them, proves the existence of God. Things appear to exist because they do so as ideas in the mind of God. The tree in the forest does indeed fall if no one is there to experience it, because it is happening within the mind of God.
Berkeley’s position went relatively unchallenged for the
next thirty years, until a young Scottish philosopher, David Hume, published
his A Treatise of Human Nature in
1739. Hume carried some of the reasoning of Locke and Berkeley further, to a
type of logical dead-end that was startling, and bore some similarities with
certain realizations of the East, in particular Buddhist thought. Hume agreed
basic approach but objected to the presence of God in his scheme, arguing that
it was both unnecessary and unsupportable by clear reason. Berkeley’s ‘God’ was an assumption, nothing
For Hume, we can be
certain of nothing but our own thoughts and perceptions—not that their content
is necessarily true, but only that we are in fact experiencing them. As Berkeley had asserted, nothing
exists without a consciousness to perceive it—esse est percipi (to be, is to be perceived)—only because we have
no means of proving the actual existence of anything outside of our mind. But
Hume argued that that necessarily includes the supposed existence of God. He
also maintained that so-called cause and effect, the cornerstone of empirical
science, was an unwarranted assumption, because in truth we never actually
perceive anything more than a succession of discrete events in time—‘constant
conjunctions’. We never perceive the actual ‘law’ of cause and effect as some
intrinsically real operation. We only perceive specific, individual events that
appear to us to coincide with each other.
The key to grasping Hume’s reasoning lies in understanding the idea of inductive inference. Inductive inference is reasoning based on making observations about patterns, and then reasoning that such patterns continue even when we are not there to observe them. (For example, by extrapolating into the future—eating an apple a day is good for me, therefore it will always be good for me). Hume criticized this reasoning in a way that was reminiscent of some of the old Greek Skeptics, in terms of his using doubt to relentlessly question our assumptions. (He did not, however, advocate living by extreme skepticism, but rather reconciled himself to the necessity of accepting inductive reasoning—it is pointless to stop eating apples, or other healthy food, just because we have no way of knowing that it will still be good for us at some point in the future—unless the knowledge comes to us in the future that eating apples is bad for us). But his essential point stood on an abstract level, that being that we cannot truthfully assume the reality about anything that involves a situation where we are not there to perceive it. All we really know for certain is the succession of ideas as they arise in our consciousness. We cannot know with certainly the cause of these ideas, whether that be God or some mechanical operation of cause and effect, or both.
Hume asserted that our
knowledge of cause and effect is based on our own mental operations. What we
perceive is not some external operation in nature, but rather our mental act of
associating perceptions together. We are seeing how our mind works, not how
things ‘outside’ of our minds work.
Hume applied similar reasoning to the self, arguing that what we assume to be the self is nothing but a succession of perceptions, memories, and ideas associated with each other. Assumptions about the discrete existence of some ‘self’ are as unwarranted about assumptions about the existence of some ‘first cause’ like God. (Although it should be noted that Hume still saw God as a type of moral imperative, meaning, that since belief in God is the foundation of moral values, it should be maintained, even if God can never be proven by reason to actually exist. Kant was later to elaborate on this point, going to lengths to distinguish between pure and practical reasoning).
Hume’s major accomplishment was to take skepticism to a sort of ultimate level, throwing the whole basis of inductive reasoning—because something is this way here and now, it therefore should be the same way over there, or in the past, or in the future—under a sharp light. He cast doubt on the whole process by which we go from specific evidence to general truths. In so doing, he continued Locke’s efforts to apply close reasoning not just to the world around us, but to the internal workings of consciousness itself.
Immanuel Kant was born in Konigsberg, Prussia (then part of Germany, today part of Western Russia) in 1724. Apart from one brief period of travel he lived in the same town his whole life, passing away in 1804, near eighty (remarkable longevity, given that his health was generally frail). He was a small, introspective man, a life-long bachelor, a university professor (of logic and metaphysics) much valued by his many students, and a man given to great inner discipline and consistent outer behavior (it was said that his neighbors could set their watches in accordance with his daily walk that he always took at precisely the same hour). As a thinker he matured slowly, only producing his greatest works when he was in his late 50s. His impact on Western philosophy from the 19th century on has been of central importance; Schopenhauer called Kant’s magnum opus the ‘most important work in German literature’ and stated that any aspiring thinker was a child until they had understood Kant. Kant’s writing is famously dense and in places opaque, employing specialized terms and, due to his lack of concrete metaphors, exceedingly dry. But his thought was deep and profound, and while some of his points have over time been discarded or surpassed, he represented a key passage in the maturation of Western wisdom.
The first (and most renowned) of his works was The Critique of Pure Reason (1781). As the title implies, it is a study of the faculty of reason itself, but not just any reason; in particular, this is reason that is independent of sensory experience. John Locke had held that all knowledge derives from what we first experience via our physical senses. Sensory input comes first—I see, hear, and feel with my hand the running water of this stream—followed by memory (next time I come to this stream, kneel down and place my hand in it again, I know to expect the same basic experience I had last time), which results in thoughts about the stream (knowledge of the stream). Without the initial sensory experience of seeing, hearing, and feeling the water of the stream, I would have no ideas or knowledge of it. This is the materialist viewpoint: all is dependent on matter.
Locke’s view had been
famously challenged by Berkeley, who argued that Locke’s thesis in fact implied
the opposite, namely that what we really know is nothing other than our own
thoughts, not the object itself. In seeing and hearing and feeling the water of
our rushing stream, what we are really knowing are these sensations and our
subsequent memory and thoughts (knowledge) about this stream. We do not truly
know the stream itself. Berkeley’s
main point is that everything we seem to know is nothing more than our mental
experience of things. Reality is therefore only to be found in ideas and
consciousness. Matter is illusion. However Berkeley added that the stream continues to
exist as an ‘idea’ even if we are not there to perceive it, because it is an
idea in the mind of God. But, according to Berkeley, the notion of a stream existing
independently of consciousness, and in particular independent of the
consciousness of God, is a fallacy. This was, basically, the Irish bishop’s
attempt to discredit and logically disprove the atheistic materialism promoted
by Locke. Hume had followed this by taking some of Berkeley’s insights to a logical extreme,
arguing that little is knowable to the human mind other than the perception of
events in close association with each other. For Hume, the ideas of God, the
self, and the scientific notion of cause and effect were all assumptions,
guesses, unwarranted attempts to explain our subjective impressions. Hume had
thus arrived at a polar opposite position to Plato, who had proposed that all
we directly experience, via our senses, is but a shadow of a higher order of
reality that we cannot normally perceive. Hume argued the opposite, that all we
truly know are our direct perceptions, with everything else being a mental
construct devised to explain these impressions.
Some forty years after the appearance of Hume’s key work, Kant’s The Critique of Pure Reason was published, in which he had set himself the formidable task of bridging the realms of religion, science, and philosophy with a coherent thesis. This was deemed necessary because of the vast gulf between these disciplines that seemed to exist at that time, a gulf having been initiated by the Copernican revolution in science along with the reasoning of Descartes, Locke, Berkeley, and Hume. On the one hand, science, chiefly via the work of Copernicus, Galileo, and Newton, had arrived at the position that the universe ran on mechanical laws of cause and effect—in effect, a type of determinism that followed naturally from Newtonian mechanics, i.e., the ability to predict accurately the behavior of objects in space and time according to fixed laws that could be defined mathematically. The basis of Judeo-Christian religion, however, was and always had been that a human has the capacity to makes choices, ones that define their morality and spiritual state. This idea seemed to be incompatible with strict causal determinism.
Kant was more than just sympathetic to science; in his earlier years he made unique contributions to the nascent science of 18th century astronomy. He was also steeped in religious conditioning, having been raised in a family of strict Christian values and a fundamentalist interpretation of the Bible. But as with all great philosophers, Kant was above all an original thinker, and had the capacity to take the existing philosophical views of that time to a previously unknown level.
Kant began by agreeing with Hume on some points—in fact, he credited Hume with waking him from a ‘dogmatic slumber’. The most essential of these was Hume’s assertion that we are incapable of truly knowing any metaphysical issues such as God or the eternal nature of the soul, because these are not phenomena or appearances, and our mind is capable only of generating thoughts about phenomena or appearances. Hume’s reasoning had led him to the final view that all laws inferred by science, such as cause and effect, were ultimately unwarranted, nothing more than elaborate assumptions. Kant, however, balked at this, believing as he did that Newton had uncovered legitimate and real knowledge of reality.
To resolve this seeming gulf between Hume’s penetrating skepticism and Newton’s discoveries of empirical laws, Kant took note of the ability of the human mind to conceive of mathematical laws, and agreed with Descartes and other rationalists that mathematics is a form of definite knowledge. We may be uncertain of most things, but we can be certain of the logic underpinning 2+2=4. How does this come about? Why is it that we can know so little for certain—for example, even whether or not we are dreaming right now—but we can be certain that 2+2=4? Or that we can be certain that all triangles have three sides to them?
The problem was this: Newton’s science, so revolutionary in its ability to explain the natural laws that surround us, was based on abstracts like mathematics and basic geometry. Yet Hume had convincingly argued that the mental processes within us could never yield real knowledge, but rather only assumptions about the things around us, a position that Kant agreed with. The only way out of the problem was to infer that abstract reasoning such as that used by Newton to formulate his laws was somehow inbuilt into the human mind.
In other words, Kant stood the whole mind-world problem on its head. Instead of the world informing the mind, it is more a case of our mind shaping the world we come to understand. It is the inbuilt structures of our mind—our hard-drive, as it were—that is giving rise to the world we come to conceive of and experience.
The key to understanding Kant’s reasoning lies in his assertion that space and time are what he called ‘a priori forms of sensibility’. In other words, when everything we think we know about reality based on our direct experience of things is taken away, what remains are the innate conceptions of space and time. These latter two are, according to Kant, inherent to our consciousness. They are essential to knowing the world. But because they are means by which we know the world, they shape our experience of appearances, rather than the other way around.
Kant did not, however, maintain that ‘nothing exists outside of our mind’. He allowed for the existence of what he called particulars, and in fact asserted that these particulars, and our association with them, were essential for any actual knowledge. Our senses yield to us experience of particulars, which our inherent reasoning—structured as it is on innate views of time and space—then makes sense of. Our senses give us raw data, but how the data is interpreted, and the universe we shape out of it, is entirely done by our mind via its a priori views of space and time. Kant argued that thought and sense are simultaneously co-active. Our experience and knowledge of a tree are not deriving solely from seeing, touching, and smelling it (as Locke had argued), nor are they based solely on thinking about it (the pure rationalist position). They are based on the activity of seeing, touching, smelling (in this case) and thinking about it all at once. But the tree we know of, and the tree we experience, is rooted fundamentally in our mind. The tree, in all ways we experience it and know it, conforms to our mind. Our mind does not conform to the tree. We can have certain knowledge of the tree, but it is ‘our’ tree, shaped by our mind’s innate structures.
Kant outlined very specifically the way in which this mental operation unfolds. He began by asserting that our mind is actively involved in ordering the chaos of raw experience into coherent thought (and eventually, knowledge), via two distinct stages. These stages were described by him as:
1. Transcendental Esthetic. By ‘transcendental’ Kant meant the part of our mind that operates independent of sensory experience—the a priori structure of the mind—that which we bring to the equation. By ‘esthetic’ he meant (in the original sense of the word) relating to sensation or feeling. In this first stage, we coordinate raw sensations via our inbuilt understanding of space and time. In applying our natural understanding of space and time to sensations, we arrive at organized perceptions. For example, standing near a tree we see it, can touch it, hear the wind blowing through its branches, and smell its fragrance. These sensations on their own amount to little, but when efficiently organized, they result in the general perception, and thus knowledge, of the tree. Kant argued that this operation of organizing the sensations into a specific perception and knowledge of the tree was not mechanical or automatic, but is being actively directed by a part of our mind. For example, when driving a car, we experience multiple sensory data coming at us at once, the simplest example being a traffic light. The color of the light may be amber (between red and green), but the situation may be different depending on where we are as we near the intersection, what other vehicles are present on the road with us, and so on. In one situation we may slow down, in another, we may speed up. But in both cases the color is amber, so clearly our basis for acting is not determined solely by the data provided by our visual sense, the color of the light. Another example: we have two numbers, 10 and 1. If we add them, we arrive at 11. If however we subtract the lesser from the greater, we arrive at 9. But in both cases we were working with the same two original numbers, 10 and 1. The end result is different because our mind is actively involved in shaping the result. It is not a passive tabula rasa, but an active organizing principle molding our experience of reality. According to Kant, this organizing operation of the mind is accomplished via its natural inbuilt understanding of space and time.
2. Transcendental Logic. This second cumbersome term was Kant’s way of defining the second stage in the mind’s conversion of raw sense data into specific thoughts and knowledge. It deals with the means by which we convert perceptions into organized thoughts and knowledge. As with the first stage, in which the mind actively organizes sensations into perceptions, so too in this second stage the mind is equally an active agent, converting perceptions into coherent thoughts. It does this via applying its inherent categories to the perceptions—categories such as quantity, quality, relation, substance, cause, and so on. These categories are inherent in the mind, that is, they are valid about an object prior to experiencing the object. The result of all this is that we come to experience an order to reality not because that order is inherent in some external reality, but because our mind is structured with a particular ordering principle. The reality we experience and have knowledge of conforms to our mind and the laws of thought, not the other way around. And this is why when we try to think about the ‘end of the universe’ (like the end of a road), or ‘what was going on before the universe began’, we encounter an intellectual roadblock. The questions register as absurdities, impossible to answer, because we are making the error of assuming that space and time are ‘real things’ outside of us, when in fact they are inherent structures of our mind.
And thus Kant’s clever
resolution of Hume’s skeptical position (we cannot know with certainty anything
like scientific laws) with the discoveries of 17th and 18th
century nascent science as led by Galileo and Newton (we can most certainly
know scientific laws with precision) was to argue that we can indeed gain
certain knowledge of the universe, but only because the basis of this knowledge
is inbuilt into the fabric of our mind. Our mind, according to Kant, is not a
passive block of marble waiting to be shaped by some external reality, but is
rather more akin to a sculptor giving specific shape to the marble of apparent external
reality; or, to use a modern metaphor, the mind is akin to a movie projector,
illuminating and giving meaning to a world, the knowledge of which is arising
from our consciousness. Kant was, in a sense, the first comprehensive ‘philosophical
psychologist’, in that his work redirected the traditional pursuit of
philosophy from analyzing things, the world, and our relation with the world,
to closely analyzing the nature of the thinker, the nature of mind itself.
The end result of all this was that, according to Kant, we cannot penetrate via reason to any ‘real world out there’—numina beyond phenomena—in any true sense. We can ‘know things’ and acquire great knowledge of how things appear to us, but it is never anything more than knowledge of appearances shaped by our own mind and its inherent nature. We can know phenomena, but not the ‘thing in itself’. It was in this way that Kant ultimately sought to reconcile religion with science. He reasoned that science can indeed gain definite knowledge of appearances (phenomena), precisely because of the inbuilt structures of the mind. But science (reason) cannot know reality beyond appearances—sensations, perceptions, and conceptions—which, he maintained, allowed an inroad for religion and faith. Reason cannot prove the existence of God (thus Kant claimed the medieval Scholastics, such as Aquinas, mistaken), but neither can it disprove it.
Kant further proposed that belief in God was a moral necessity, without which there was no basis for ethics, noble decisions, or as the modern expression has it, ‘taking the high road’. In an inner version of the social separation of church and state, Kant sought a sharp distinction between reason and faith that allowed, in his view, for optimum functioning of both. The essence of his moral teaching, what he called the ‘categorical imperative’ (similar to the Golden Rule), he defined as ‘Act only according to that maxim whereby you can, at the same time, will that it should become a universal law’. That is, in questioning a specific act, we should ask ourselves if it would be right for this act, and its consequences, to apply to everything. In asking ourselves, ‘should I steal?’ we apply that universally, asking ‘should everyone steal?’ with the obvious answer being ‘no’, and so on.
Kant’s reasoning, building
on, elaborating, and developing the insights of Descartes, Locke, Berkeley,
Hume, Newton, Copernicus, and others, ended with a position that involved a
definite schism between the subjective reality of man, and the assumption of
any knowable objective reality via reason alone. Man is, in a sense, alone in
his mind. Kant did, however, hold that certain elements of the human mind were
based on absolutes, such as a priori
understandings of space and time—though subsequent developments in 19th
and 20th century science and philosophy, via the revelations and
insights of Darwin, Nietzsche, Freud, Einstein, Heisenberg, and many others,
laid siege to even this basic bastion of Kant’s reasoning. Relativism,
uncertainty, and constant change were the order of the day as the very idea of
anything being ‘absolute’ took a beating.
Copyright 2011 by P.T. Mistlberger, all rights reserved.