Topics are arranged alphabetically in the INDEX.

Monday, December 29, 2014

The Story of Ontology

“The real question is why is there “being”? The existence of existence is amazing, awesome.”
Gerald Schroeder

Alice C. Linsley

In our study of epistemology, we encountered philosophers who recognized the importance of the imagination:  Hume, Kant, Kierkegaard, even Berkeley. Imagination plays a key role in this story of ontology.

Imagine that you are a spider weaving a web. As a master web-weaver how much thought is directed toward the creation of the web? Is this "ready-at hand" labor, as Heidegger suggests? What role does consciousness play in your actions?

Do you perceive of the web as the entire universe? Probably not, since you fabricated the web in such as way that it extends through air/space, and you are aware that you didn't fabricate the air/space.

Your construction of the web is a matter of daily coping. It is essential to trap other beings: flies, gnats, etc. This means that you are conscious of other beings in your universe.  The web is the spider's way to acquire nourishment to sustain its life, but does it recognize the web as a bounded ontological context?

There is the reality that the web will be broken and must be repaired or rebuilt. Is the spider's web-weaving existence pitiful? Does the spider wonder about the futility of his daily existence?

Of course, spiders do not reason as humans, but this illustrates how humans think about our existence. We fabricate from what we have and we think we are creators. Why is that? We recognize the existence of other entities in our world, especially those upon which we depend. We understand that things break in our world and sometimes the very web of our existence crashes. We grasp intellectually that there are other universes, but we do not know them because they are beyond our bounded context, our consciousness. Often our routines of daily existence cause us to wonder if all this effort is worth it.

The philosophical study of theories of existence and being is called "ontology" and it is probably my favorite area of philosophical study. The term "ontology" is derived from two Greek words: onto (being) and logia (written or spoken discourse).

In this unit, we will look at the nature of being, becoming, and existence (even extinction). In other words, we will explore the web, the air, the relationship of the web and the air, and the relationship of the web in air to the larger universe called "reality." Because the whole story of reality is an impossible tale for humans in our bounded ontological context, we will have to narrow our exploration. We will not wander far from metaphysics. We will not discuss ontology related to aesthetics or to ethics, though ontology determines and informs views of beauty, goodness, fairness, etc.

I hope to tell the story of ontology by staying with concrete particulars like air, fire, water and earth. Let us consider an illustration that employs fire.

When you build a fire, do you believe you have created the element of fire or do you recognize that you have merely started a process? When you contain the fire so that it will not spread, do you also contain the products of the process you started, the smoke and chemical reactions? You are safe while the fire is contained in a small space, but at the same time, you are not safe if the smoke and fumes are contained in the same small space. Apparently, the value or benefit of something being contained (bounded) is relative.

If these illustrations that speak of air and fire remind you of the pre-Socratic debates about primal substance, your thinking is headed in the right direction! Why did Thales, Anaximander, Anaximenes not agree as to the substance that makes existence possible? Because each had to interpret their experiences, and no two humans can have exactly the same interpretation. The art and science of interpretation is called hermeneutics. Maybe ontology is simply hermeneutics, or maybe hermeneutics is ontology.

That is what Martin Heidegger (1889-1976) thought. He developed this in his book Ontology--The Hermeneutics of Facticity (1988). The book is a compilation of the lectures he delivered at the University of Freiburg during the summer of 1923. In these lectures, Heidegger reviewed and critically appropriated the hermeneutic tradition, beginning with Plato, Aristotle, Augustine and including the thought of Schleiermacher (1768-1834) and Dilthey (1833-1911). He attempted to reformulate the question of being on the basis of facticity and the everyday world (phenomena/phenomenology).

Heidegger explored the structures of human consciousness, the categories of experience of being, what he called "Dasein." He is one of the philosophers whose work we will investigate in this unit on ontology. Another is Jacques Derrida, an Arabic-speaking, North African Jew who explored the relationship between ontology and theology, calling this "ontotheology," a term he picked up from Immanuel Kant. Derrida's deconstruction employs interpretative principles that have the effect of restoring a more ancient Afro-Asiatic approach to meaning (binary oppositions). He identifies the importance of context and presence, and initiates a deeply ontological conversation. A fundamental assertion of deconstruction is that "there is no outside-text" (il n'y a pas de hors-texte). This oft-quoted phrase from Derrida's Grammatology means simply (or complexly) there is nothing outside of context.

As we came to recognize in our study of epistemology, there are limits to what humans can know. There are perplexing questions that philosophers have never resolved. These include the mind-body problem: how can that which is not extended act on the material world?; and the problem of induction: when is the evidence sufficient? We hit the same roadblock when we explore the central questions of ontology: What really is?; What constitutes being? Plato's Forms was an approach that sought a way around the roadblock. For Plato, the objects perceived as existing have a nature that is beyond what is perceived by the senses. Things are not what they seem to be because they are reflections of the true Forms.

And that takes us to our next illustration. This one uses the element of water and comes from Plato's Republic (X. 602c). The "oar in the water" illustration demonstrates how circumstances (contexts) can affect the individual's perception. Consider an oar half submerged in water. Beneath the water's surface the oar appears to be bent. It appears to have a different trajectory. Many have found this illustration trite. J.L Austin's comment reflects the modern attitude: "Does anyone suppose that if something is straight, then it jolly well has to look straight at all times and in all circumstances?" (Sense and Sensibilia, pages 21 and 29) However, Plato's illustration is less about sensibility than it is about his "two worlds" metaphysics. It is used to make his point that, since we can have only knowledge of Forms, we cannot have any false beliefs about Forms. What is below the surface, though refracted, is yet the very real projection of what is above the surface.

Austin appears to be unfamiliar with the Nilotic background of Plato's belief in universals. Indeed, this binary perception of reality was already ancient in Plato's time. Austin attempts to dismiss this, writing, “Ideally, I suppose, a discussion of this sort ought to begin with the very earliest texts; but in this case that course is ruled out by their no longer being extant. The doctrines we shall be discussing—unlike, for example, doctrines about 'universals'—were already quite ancient in Plato's time.”(Sense and Sensibilia, page 2) (Italics mine for emphasis.)

We do keep coming back to this binary feature. In telling the story of ontology, we cannot escape it. Our human anatomical structure, with bilaterialism, makes greater range of movement possible. Our bicameral brain/mind makes greater complexity of thought possible. Daily we are faced with the binary pattern of universal sets: male-female; night-day, and most significantly, life-death.

The mind makes distinctions along binary lines. We tend to think axiomatically: good-bad, normal-strange; one-many; now-not yet, etc. The mind recognizes that something can be and yet not be: the Biblical understanding of the Kingdom of God. Something can exist (actuality) while not yet existing. The kingdom is here now and yet still to come (potentiality), if we take Biblical eschatology seriously.

Aristotle's understanding of the elements now comes into play. He wrote, "The elements ... cannot be eternal. It is a matter of observation that fire, water, and every simple body undergo a process of analysis [i.e., destruction]. (On the Heavens 304b23). Fire can be destroyed by water. Water can be evaporated by wind/air. Vacuums exist, so air cannot be said to be everywhere at all times. And then there is earth, our final illustration.

The Greek comic poet and "wise man" Epicharmus (540-450 BC) was known to both Plato and Aristotle. He expressed a widely held ontological idea: "Life is compounded and broken up, and again goes whence it came; earth indeed to earth, and the spirit to upper regions." Many regarded the elements as deities. In this view, the gods are the winds, the water, the earth, the sun, the fire, the stars. To which Epicharmus quips: "But I think that the only gods useful to us are gold and silver."

Ben Sira (the author of Ecclesiasticus) writes, "How can dust and ashes be proud? Even in life the human body decays." (Ben Sira 10:9) He calls man "dust and ashes" and asserts that all things that are of the earth return to the earth. "Dust to dust. Ashes to ashes." The connection seemed obvious to those who came upon sites where humans had been buried long before and all that remained was an outline of ash and dust. This sight necessarily confronts us with the reality or unconcealment (aletheia) of our death as non-existence, what Heidegger termed "negation."

Negation means to deny, and Heidegger is concerned with a specific form of denial: the denial of one's non-existence, the refusal to face the reality of one's death. How we live and die tests the authenticity of our being. Awareness of my mortality changes how I live. For Heidegger, the proper response to being as a human is reflection on existence as a way to tug the veil that covers essence. We must do this to own our being as individuals living in the everyday world. We must look at the dust of the earth and say to ourselves, "That's what I am and to dust shall I return." Yet, as soon as we say those words, we know we have spoken a half-truth. The human is more than dust. We find ourselves turning from our well considered philosophical pretenses to language that has a God concept as its first order predicate. This has happened in the thought of many philosophers as they aged and approached death: Heidegger, Wittgenstein, and Derrida are examples. By avoiding the use of the word God and by replacing it with a god concept, they have unveiled a presence that has always been there. The presence serves as a function whereby existence is explored as second order extension. This "turning" (as Heidegger called it) appears to be a sign of authentication of individual being.

Søren Kierkegaard wrote, “Imagination is what providence uses to take men captive in actuality, in existence, in order to get them far enough out, or within, or down into existence. And when imagination has helped them get as far out as they should be - then actuality genuinely begins.” (The Two Ages)

Friday, December 26, 2014

Philosophy: The Most Impractical Practical Tool

One of the many small surprises of the recession has been a significant growth in the number of philosophy majors, according the the Philadelphia Inquirer. It has slightly exceeded the growth of enrollments in the last ten years; many other humanities and social science fields have just kept up. At the University of California at Berkeley, despite or because of the state's economic turmoil, the number of majors has increased by 74 percent in the last decade.

What makes philosophy different? It can seem self-absorbed; philosophers themselves joke about Arthur Koestler's definition: "the systematic abuse of a terminology specially invented for that purpose." But it also is a tool (like history and religious studies) for thinking about everything else, and every profession from law and medicine to motorcycle maintenance.

Read it all here.

This defense of philosophy as practical is ironic considering that Aristotle said the exact opposite and conditioned the supreme value of philosophy precisely on its non-practicality. That said, the philosophy classroom is the single space in American public education where anything, absolutely anything can be discussed. In the present environment of bureaucratic intrusion, students are glad to find such a space.

Where else do students get to discuss this?

Related reading: St. Paul's Application of Greek Philosophy; INDEX of Topics at Philosophers' Corner

Tuesday, December 23, 2014

Student Graphics Illustrate Fallacies

Anna Price – Chronological Snobbery
(Copy Reads): The mindset that sees an idea, way of thinking, culture, art, or science of an earlier time as inferior, based solely on the assumption that whatever is newer is better. For example: "It is really hard for me to enjoy Medieval art – after all, these are people who didn't even have indoor plumbing."

This is an excellent project! See more examples of the students' posters here.

Related reading: Fallacies; Logic on the Lighter Side; Why Logic Should Be Taught in Schools

Tuesday, December 2, 2014

Theories of Knowledge - Part 4

"The universe is full of magical things patiently waiting for our wits to grow sharper."-- Eden Phillpotts

"In truth, truth inhabits fiction as the master of the house."--Jacques Derrida

"The world is governed more by appearances than realities, so that it is fully as necessary to seem to know something as to know it."--Daniel Webster

"Hell is truth seen too late."--Thomas Hobbes

Hume and Kant
Alice C. Linsley

David Hume categorized all objects of human reason into two groups: Relation of Ideas and Matters of Fact. This is often referred to as "Hume's fork" and can be further investigated in An Enquiry Concerning Human Understanding, Section IV, Part 1. Here we read: "All the objects of human reason or enquiry may naturally be divided into two kinds, to wit, Relations of Ideas and Matters of fact. Of the first kind are the sciences of Geometry, Algebra, and Arithmetic... discoverable by the mere operation of thought... Matters of fact, which are the second object of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing."

The truth claims that Descartes posed when he introduced the evil deceiver argument are in Hume's second category - "relations of ideas" and Descartes further developed the argument that all real knowledge consists of relations of ideas, including knowledge of the material world. Descartes thought that the material world can be explained by physical laws of causation and that one day physics would be established as an a priori science along with geometry and algebra. Hume, on the other hand, sought to demonstrate that science is not a priori. Instead, Hume argued that there is never certainty concerning causes and effects by using reason alone. Science requires experimentation and observation, and there is always the possibility that the next experiment might not provide the same results or conform to the hypothesis as did earlier experiments.

This radical doubt poses a problem for scientists. It means that the scientific method cannot be said to ascertain beyond doubt. This is Hume's problem of induction. Inductive methods predict or infer and are essential in scientific reasoning. One cannot assume that something is immutable and necessary because it has always or usually been reliable in the past. Though 20 experiments produce the same results, we have no certainty that the results will be the same after experiments 21, or 32 or 45. Though the sun has risen daily since the founding of our solar system, we have no certainty that it will always do so.

In 1953, Richard Rudner published “The Scientist qua Scientist Makes Value Judgments,” in which he argued that since no hypothesis is ever completely verified, in accepting a hypothesis the scientist must make the decision that the evidence is sufficiently strong to warrant the acceptance of the hypothesis. The problem of induction which David Hume framed so precisely is really a problem of decision about which action to take, not proof of the fallibility of science in general. For Hume this is where the element of the human imagination comes in to play. In Hume's view the most ordinary interactions and common observations of bare facts involve active imagination. They do not represent passive perceptions of the world. His critique of metaphysics involves a criticism of what he sees as lack of imagination or blind imagination. In his view, the errors of philosophy arose from the fact that imagination determined human thought more than people recognize.

Immanuel Kant

Immanuel Kant (1724-1804) was aroused from his "dogmatic slumbers" by David Hume. Kant thought that Hume went too far in his skepticism about the capability of the inductive method of science. He saw greater agreement among scientists than among philosophers and thought that, unlike metaphysics, the motions of material objects are governed by laws. Everything that happens is determined by antecedent happenings or prior conditions. But this caused a problem for Kant's anthropology. If everything is predetermined in the universe, how is it that humans have free will?

Kant concludes that the human has free will to choose to fulfill his duty at any given moment and the universal moral law concerns performance of duty, regarding humanity as an end in itself rather than as something to be used to achieve selfish ends.

Much of what Kant wrote is an attempt to defend the Christian understanding of God and the value of reason against Hume’s skepticism. In his Critique of Pure Reason, Kant agrees with Hume that there is no absolute ground to assume the existence of God. However, against Hume, he adds that the idea of God is intrinsically connected to happiness and morality as the “ideal of the supreme good.” In his later treatment on Logic (1800), Kant argues that the idea of God is proved only through the moral law and only with “the intent so as to act as if there be a God.” 

Kant claimed that virtuous living results from practical reason. Schopenhauer discredited Kant’s moral system mainly because it is based on individual duty. He believed that the individual’s sense of duty cannot be the grounds for every moral decision or action. Instead he emphasized that a study of the great world religions suggests a universal moral code which he expressed in these words: “Don't do to another what you don't want done to you.” Schopenhauer claimed that virtuous conduct has nothing to do with reason and may even be opposed to it, as with Machiavelli’s rational expediency. In the face of a bloody civil war in Italy (1502-03) that involved mass killing, street assassinations, and widespread anarchy, Machiavelli wrote:

I say that every prince ought to desire to be considered clement and not cruel. Nevertheless he ought to take care not to misuse this clemency. Cesare Borgia was considered cruel; notwithstanding, his cruelty reconciled the Romagna, unified it, and restored it to peace and loyalty. And if this be rightly considered, he will be seen to have been much more merciful than the Florentine people, who, to avoid a reputation for cruelty, permitted Pistoia to be destroyed. Therefore a prince, so long as he keeps his subjects united and loyal, ought not to mind the reproach of cruelty; because with a few examples he will be more merciful than those who, through too much mercy, allow disorders to arise, from which follow murders or robberies; for these are wont to injure the whole people, whilst those executions which originate with a prince offend the individual only.

It is possible to argue with Machiavelli that reason might lead to actions that in most contexts are regarded as immoral.

Kant's synthetic a priori knowledge

One of Kant's contributions is in the area of logic. He recognized a class of propositions termed "synthetic a priori." Such propositions are distinct from a posteriori judgments based on observation and experimentation. These judgments, being of an empirical nature, are largely descriptive; that is they define rather than inform. In this class of propositions we find propositions such as "a bachelor is an unmarried man" or "swans are waterfowl."  A synthetic judgment, informs, not merely defines. Typically, synthetic judgments are associated with a posteriori knowledge (knowing the particulars) and analytic judgments are associated with a priori knowledge (knowing the universals). An example of a synthetic a posteriori judgment is “all swans are white.” This is synthetic because whiteness is not a necessary part of the concept of swan.  The statement is also an example of an a posteriori proposition because the only way to find out if all swans are white is from observation and experience.

Kant argues that mathematics and the laws of physics contain synthetic a priori knowledge. For example, “7 + 5 = 12” is a priori because it is a necessary and universal truth we know independent of experience, and it is synthetic because the concept of “12” is not contained in the concept of “7 + 5.” Kant argues that the same is true for the laws of physics such as “for every action there is an equal an opposite reaction.” Because such laws apply universally, they must be a priori knowledge, since a posteriori knowledge only tells us about particular experiences. The fact that we are capable of synthetic a priori knowledge suggests that pure reason is capable of knowing metaphysical truths.

Kant suggests something very like Hume's understanding of the mind. Much of what we consider to be reality is shaped by perception. Kant agrees with Hume that the mind does not passively receive information provided by the senses. Rather, it actively shapes and makes sense of that information. If all the events in our experience seem to take place in a temporal progression, that is our minds arrangement of sensory experience. If we perceive that some events appear to cause other events, that is because our mind's cause-effect arrangement of events. According to Kant, the mind is constrained to perceive or experience sensations in time and space and according the laws of causation. He argues that time and space are intuitions of our faculty to sense things, and physical laws such as gravity and inertia are intuitions of our faculty to understand things.

Related reading:  Theories of Knowledge - Part 1; Theories of Knowledge - Part 2; Theories of Knowledge - Part 3; Why David Hume Was Wrong: Immanuel Kant, What is Enlightenment?

Saturday, November 29, 2014

Theories of Knowledge - Locke and Hume

"If you would be a real seeker after truth, you must at least once in your life doubt, as far as possible, all things."--René Descartes

Alice C. Linsley

Francis Bacon insisted that methodical observation and experimentation (the scientific method) can progressively increase human knowledge and benefit all of humanity. Bacon also demonstrated through his experiments that the senses can be fooled and thus raised doubt about "common sense" ideas. Bacon insisted that true knowledge must begin with doubt. He wrote, "If a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts, he shall end in certainties." --Francis Bacon (1605) The Advancement of Learning, Book 1, v.8

Descartes felt it necessary to one reject entirely all beliefs about which there is the slightest doubt. He wanted to build a system of belief based on certainty. Descartes' point of certainty was his own rational existence:  "I am thinking, therefore I am existing." He wrote in Discourse on Method, "But I soon noticed that while I thus wished to think everything false, it was necessarily true that I who thought so was something. Since this truth, I think, therefore I am, was so firm and assured that all the most extravagant suppositions of the sceptics were unable to shake it, I judged that II could safely accept it as the first principle of the philosophy I was seeking." (Part Four on "Proofs of the Existence of God and of the Human Soul)

Descartes develops this as a proof for the existence of God. He continues, "After that I reflected upon the fact that I doubted, and that in consequence, my spirit was not wholly perfect, for I saw clearly that it was a greater perfection to know than to doubt. I decided to ascertain form what source I had learned to think of something more perfect than myself, and it appeared evident that it must have been from some nature which is in fact more perfect... I was not the only being in existence..., and it followed of necessity that there was someone else more perfect upon whom I depended and from whom I had acquired all that I possessed. For if I had been alone and independent of anything else, so that I had bestowed upon myself all that limited quantity of value which I shared with the perfect Being, I would have been able to get from myself, in the same way, all the surplus which I recognize as lacking in me, and so would have been myself infinite, eternal, immutable, omniscient, omnipotent, and, in sum, I would possess all the perfections that I could discover in God."

Here Descartes articulates a form of the argument from design. The reasoning goes like this:  I find imperfection in myself and I recognize it, which means that I have consciousness of something or someone more perfect than myself. That being so, I must have been designed by that greater Perfection. Descartes wrote: "The very principle which I took as a rule to start with, namely, that all those things which we conceived very clearly and very distinctly are true, is known to be true only because God exists and because he is a perfect Being, and because everything in us comes from him. From this it follows that our ideas or notions, being real things which come from God insofar as they are clear and distinct, cannot to that extent fail to be true."

Descartes contributed to the development of new theories of mind and consciousness. He defined thought "to include everything that is within us in such a way that we are immediately aware [conscii] of it. Thus all the operations of the will, the intellect, the imagination and the senses are thoughts."

John Locke (1632-1704)

The British empiricist John Locke believed that experience alone is the basis of all knowledge. He argued this against Descartes's position that the human mind holds innate ideas.

Locke contributed to the development of theories of consciousness. If a thought is something “within us" of which we are conscious, what is the nature of consciousness? Locke insists that the mind is empty at birth, a tabula rasa. All our ideas are shaped by experience; sensations, and reflections.

Locke wrote that "the little and almost insensible impressions on our tender infancies have very important and lasting consequences." He argued that the "associations of ideas" that one makes as a child are very important because they are the foundation of the self. He warned against letting "a foolish maid" convince a child that "goblins and sprites" are associated with the dark of night for "darkness shall ever afterwards bring with it those frightful ideas, and they shall be so joined, that he can no more bear the one than the other." Locke's theory of association influenced educational theory up to the nineteenth century. Educators warned parents not to allow their children to develop negative associations. 

David Hume (1711-1776)

The Scottish philosopher David Hume continues the empiricist trajectory, developing the consequences of Locke's thought. Hume held that in the search for truth, we cannot rely on the common-sense pronouncements, popular notions, or metaphysical speculation. Building on Locke's epistemology, Hume tried to describe how the mind works in acquiring what is called knowledge. He concluded that no theory of reality is possible; there can be no knowledge of anything beyond experience. He wrote, "If we take in our hands any volume; of divinity or school metaphysics, for instance; let us ask, does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion." (Enquiry Concerning Human Understanding)

In Hume's view, normal human reasoning is flawed and this raises radical doubt about all claims to know something. When we give the reasons for our beliefs about the world, we find that many of the offered explanations are contradictory. For example, one person asserts that something is true for them, but another denies that it is true in their experience. How can something be said to be true for one person and not for another? After exposing a series of contradictions within the human reasoning process, Hume reaches this conclusion: "The intense view of these manifold contradictions and imperfections in human reason has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another." (Treatise of Human Nature)

To the epistemological conversation he adds an additional criterion: do not consent to any belief that is not found to be universally true. This is the ultimate test of truth: that it should be demonstrated mathematically as a universal truth or, following Sir Isaac Newton, as a universal physical law.

Hume conceived of philosophy as the inductive, experimental science of human nature. He sought to discover the causes of human belief. For Hume, this is the proper work of philosophy. Book I of the Treatise of Human Nature and all of the first Enquiry represent his attempts to do exactly this. He wrote, "my intention never was to penetrate into the nature of bodies, or explain the secret causes of their operations. For besides that this belongs not to my present purpose, I am afraid, that such an enterprize is beyond the reach of human understanding, and that we can never pretend to know body otherwise than by those external properties, which discover themselves to the senses." (Treatise of Human Nature, Sec. V)

Despite Hume's radical empiricism, he continued to value common sense, and apparently did not take his own skepticism, such as the problem of induction, to the extreme that others did after him. He recognized that the consequences of his radical skepticism clashed with common sense and his concern for enlightenment scholarship.  [Antony G Flew, A Dictionary of Philosophy, rev 2nd edn (New York: St Martin's Press, 1984), p 156].

Friday, November 28, 2014

Theories of Knowledge - Bacon and Descartes

"Knowledge is the rich storehouse for the glory of the Creator and the relief of man's estate"-- Francis Bacon

"I think, therefore I am."--Rene Descartes

"Our only hope, then is in genuine Induction... There is the same degree of licentiousness and error in forming Axioms, as in abstracting Notions: and that in the first principles, which depend in common induction. Still more is this the case in Axioms and inferior propositions derived from Syllogisms."--Francis Bacon

"A wise man, therefore, proportions his belief to the evidence."--David Hume

Alice C. Linsley

Epistemology explores questions related to knowledge. It is concerned with how knowledge can be acquired and how to substantiate truth claims. Is it possible to know the true nature of something? What can be known? What are the limits of human understanding?  How can I verify that this claim is true? Does our knowledge represent reality as it really is? Does innate knowledge exist? Is it possible to understand natural phenomena solely on the basis of observation and the senses?

From the dawn of human existence, the need to know about things in nature has contributed to human survival.  It moved early humans to explore and discover new places.  It motivated them to sample berries, nuts and grains. Through trial and error they came to know which fruits were good and which would make them sick. Archaic human populations gained knowledge by interacting with their environments, by observation of patterns in nature,and by reasoning.

Plato would say that the earliest humans had some innate knowledge of Truth, assuming that they had souls. Ritual burial, symbolic markings, primitive counting devices, and stone works such as the 70,000 year old carving of a python in the side of a mountain in Botswana, indicate that archaic human populations were essentially "religious" and concerned about knowing what is beyond their day-to-day lives.

Some ideas we have about reality may have been found to be inadequate. If we are thoughtful people, we will re-evaluate these ideas. Throughout history, philosophers have shown that many ideas are not true, or at only partially true, and therefore not reliable. We are wise to exercise a certain amount of doubt, especially when it comes to following people who have shown themselves to be careless and/or pig-headed.

Francis Bacon (1561-1626) showed that the senses can be fooled and that appearances can be deceptive. Yet more than any other thinker of his time, he urged that the senses be used in a methodical way to discover the nature of heat, light, wind, motion, the tides and the stars and even the human being. The future belongs to "Those who aspire not to guess and divine," wrote Bacon, "but to discover and to know... who propose to examine and dissect the nature of this very world itself, to go to facts themselves for everything."

Sir Francis Bacon
Bacon is regarded as the father of modern empiricism. His method of investigating natural phenomena involved inductive reasoning, in contrast to deductive reasoning, which had dominated science since Aristotle.  Bacon introduced an inductive method of testing and refining hypotheses by observing, measuring, and experimenting. An Aristotelian might deduce that water is necessary for life since it is evident that organisms cannot survive without water. A Baconian would test the hypothesis by experimenting. The results of those experiments would lead to more informed conclusions about the necessity of water for organic life.

After centuries of knowledge shaped by Roman Catholic beliefs, Bacon issued a summons to feast on knowledge acquired by the senses, through experimentation and logical principles. He organized his first book the Advancement of Learning in two parts. The first was called Experientian Literata. In this section he proceeds from one experiment to another. The second part, the Interpretation of Nature, moves from experiments to general principles or axioms, and then on to new experiments. Bacon loved to innovate!

In The Advancement of Learning and in New Organon, Bacon sets forth the idea of technological and scientific progress.  He is the first to articulate the popular notion that human advancements are progressive, rather than cyclical, static or in linear decline. He held a Utopian view of the gradual acquisition of knowledge, and he advocated this progressivism with the ardor of an evangelist.

The philosopher in the trajectory of empiricism that embodies Bacon's method most fully is David Hume. In An Enquiry Concerning Human Understanding (1748), Hume wrote, "A wise man, therefore, proportions his belief to the evidence. In such conclusions as are founded on an infallible experience, he expects the event with the last degree of assurance, and regards his past experience as a full proof of the future existence of that event. In other cases, he proceeds with more caution: He weighs the opposite experiments: He considers which side is supported by the greater number of experiments: to that side he inclines,with doubt and hesitation; and when at last he fixes his judgement,the evidence exceeds not what we properly call probability. All probability, then, supposes an opposition of experiments and observations, where the one side is found to overbalance the other, and to produce a degree of evidence, proportioned to the superiority. A hundred instances of experiments on one side, and fifty on another, afford a doubtful expectation of any event; though a hundred uniform experiments, with only one that is contradictory, reasonably begets a pretty strong degree of assurance." (Chapter 10, Concerning Miracles) These words could have been written by Francis Bacon himself!

René Descartes (1596-1650)

Just as Bacon is considered the first modern empiricist, so René Descartes is regarded as the father of modern philosophy. He contributed to the philosophical project in many areas:  theories of consciousness, the argument from design, and moral philosophy. He is an important figure in epistemology because he developed a method of weighing evidence that allowed for innate ideas.

Descartes' method involved setting aside his previously held views in order to begin from a point of logical certainty. He believed that most of what he "knew" was not reliable. He wrote, "All that up to the present time I have accepted as true and certain I have learned either from the senses or through the senses; but it is sometimes proved to me that these senses are deceptive, and it is wiser not to trust entirely anything by which we have once been deceived." (Meditations on First Philosophy) Here Descartes sets out a principle that guided his epistemology: If there is any reason for doubt, then the entire category should be treated as doubtful and unreliable. His method was simple: don't accept anything as true if there is the slightest possibility that it is not true. This is known as the Method of Cartesian Doubt. Modern philosophy begins with doubt.

In attempting to toss out what he had believed and later doubted, in order to construct a system of belief based on certainly, Descartes began with this: "I think, therefore I am" or "I am thinking, therefore I exist." (Cogito ergo sum.)  His awareness of his own self constituted the point of certainty from which he intended to consider and verify knowledge.

Descartes is often considered the founder of modern philosophy with its bent toward empiricism. He conceived of all the branches of science as a whole and sought a methodology that worked toward a unified science. He wrote that “philosophy is like a tree: the roots are metaphysics, the trunk is physics, and the branches that issue from the trunk are all the other sciences..." The metaphor is strange in the context of what he attempts. Descartes attempts to show that what is not mental or mind-like is extension, that is, it takes up space. However it is not possible to speak of philosophy as taking up space as a tree does. Here we recognize an inconsistency in Descartes’ thought.

Descartes viewed mind and body as distinct entities or substances. He concluded that the basic features of material objects are geometrical. They have size, shape, volume, etc.  The mind can not be measured in the same way.  It is characterized by thinking, reasoning and imagination. For Descartes the essential property of the mind is that it thinks and the essential property of the body is that it is “extended.” Extension is the property of taking up space. In this view, action or movement is explained by the impact of one extended object upon another. How then can mental events, that are without extension, have an impact on objects that take up space? Descartes is a great nightmare for the paranormal cults!

Descartes has been criticized for separating mind and matter into two distinct substances and failing to explain how they may be said to be related and/or interactive. This Cartesian dualism gave rise to fascinating reflections on the Mind of God, which Descartes believed to be the Principle that unites the realms of Mind and Matter. George Berkeley (1685-1753) would take this to a logical extreme with his immaterialism and the idea that all things are an extension of the Mind of the Creator.

Cartesian doubt influenced many thinkers of the modern era. Soren Kierkegaard (1813-1855) is one of them. He began is operations with three theses that he came to appreciate in the conversations of many modern philosophers. They are: (1) philosophy begins with doubt; (2) in order to philosophize, one must have doubted; and (3) modern philosophy begins with doubt.

Thursday, November 27, 2014

Theories of Knowledge - Part 1

"It is owing to their wonder that men now begin, and first began, to philosophize."-- Aristotle

"This sense of wonder is the mark of the philosopher. Philosophy indeed has no other origin."-- Plato

Alice C. Linsley

In archaic communities - between 50,000 and 20,000 years ago - knowledge was gathered from observation of fixed patterns in nature. The sun's rising and setting; the facts of human and animal reproduction; the signs of coming storms; the solidity of rock, the softness of moss and rich humus, etc.

Binary distinctions were observed such as male-female, night-day, and dry-wet. The observation of distinctions in the patterns of nature suggested a fixed order which archaic people attributed to the Creator. The moral law of archaic communities discouraged behaviors and practices that violate the fixed order in creation in order that the Creator might not be offended.

Blood and water were regarded as the fundamental substances of life because it was evident that all creatures needed these to survive. The shedding of blood was regarded as a serious matter and the blood guilt was mediated by priests and shamans, the two oldest religious offices. These offices served similar functions within their communities but represent distinct worldviews.

As early as 100,000 years ago, humans observed certain rituals surrounding the burial of their death. These practices included burial in red ochre and the inclusion of personal articles. An example is the double burial at Qafzeh in Israel, believed to be a double burial of a mother and child. The bones have been stained with red ochre.

From very early times, the soul has been viewed as a essential part of the human and one that has an eternal existence. There are different views as to how the soul continues to exist after the body dies: Sheol (a holding place until the Last Day); reincarnation, and transmigration of a limited number of souls. Plato held the latter view.

Plato believed that Truth is immutable and eternal and therefore considered knowledge of Truth to reside in the eternal Soul. He held that the trained mind could 'recollect' or 're-cognize' the true Forms and thereby "know' what is true and real. Aristotle built upon Plato's thought, but took it in a different direction. According to Aristotle, animate beings can move only because they have a soul. He thought that knowledge came through interaction with the external world. The soul takes on the imprint of sensations. When I press the soft tissue of my finger tip against a hard object, for example, an impression is made on my finger tip. Likewise, impressions are made on the soul and this results in knowledge. (On the Soul II 5)

For Aristotle all knowledge, even the imagination, must begin with information acquired through the senses. However, to grasp the relationships among abstract forms the soul reasons logically. (On the Soul III 4) Although experience is a key to all demonstrative knowledge for Aristotle, he also understood that the metaphysical study of "being qua being" must attempt to understand why things happen the way they do. For Plato, the soul is the reservoir of what exists truly. For Aristotle, the soul's what can only be understood by the mind's why.

Related reading: Overview of Afterlife Beliefs Through History; Theories of Knowledge - Part 2; Ethical Concerns of Archaic Communities; Early Metaphysics: Primal Substance, Theories of Knowledge - Part 3; Theories of Knowledge - Part 4; Lloyd Gerson, Goodness, Unity and Creation in the Platonic Tradition

Friday, November 14, 2014

Leibniz Critiques Descartes

Descartes' project lead him to a problem that he could not overcome: the problem of the interaction between mind and matter. How it is that the mind can influence events? How does the spirit push around material objects? He brought us to the brink of the problem, but then failed to explain the interaction of mind and body or spirit and matter. Gottfried Wilhelm Leibniz (1646-1716)  said, "Monsieur Descartes seems to have given up the game so far as we can see." Descartes dropped the ball, but the ball kept rolling and was picked up by other great thinkers. One of those thinkers was the German rationalist Leibniz who put forward an "impressive interlocking metaphysical system."

Leibniz conceived of reality as consisting of God and non-composite, immaterial, soul-like entities called "monads." Leibniz believed that things seem to cause other things because God pre-ordained harmony between all things in the universe.

He was scornful of Descartes' failure to argue his mind-body dualism to its logical end, but he proposed his own version of the mind-body dualism. In his writings, Leibniz talks a good deal about machines such as watches and clocks. In Section 17 of the Monadology he presents an argument about the relationship between mentality and machines. Leibniz’s “mill argument” is as follows:

Moreover, we must confess that perception, and what depends upon it, is inexplicable in terms of mechanical reasons, that is through shapes, size and motions. If we imagine that there is a machine whose structure makes it think, sense, and have perceptions, we could conceive it enlarged, keeping the same proportions, so that we could enter into it, as one enters a mill. Assuming that, when inspecting its interior, we will find only parts that push one another, and we will never find anything to explain a perception. And so, one should seek perception in the simple substance and not in the composite or in the machine. (GP VI, 609/AG 215)

Imagine walking around inside a large mill or factory. You are able to see the mechanics and observe the processes, but you do not find a "brain" in the factory to explain how the factory thinks and acquires knowledge. Things operate according to their inventor's design. They run and produce, as is true also of the human, so why do we assume that the human brain involves thinking? Mechanical processes do not explain thinking, therefore, external operations and mental operations are two distinct things. This is Leibniz's version of dualism.

Leibniz’s Critique of Descartes

Leibniz observed that if life is a dream (as Nietzsche asserted), it must still have structure. He applied this idea to the relationship of objects. According to Leibniz, every entity whether mental or physical is independent and constitutes a “monad.” Each monad is fixed or determined in its properties according to its essence or nature. Whatever form an entity takes or whatever happens to an entity is entirely determined by its essential characteristics and not from the influence of any other entity (a version of essentialism).

Leibniz overcame Descartes’ dualism by claiming that there is no connection between mind and body, but a harmonization of all (Monism) on the level of kinetic energy. Leibniz believed that the world is not as Descartes claims. It has structure, but what we see is merely the visible outcome of infinitely numerous spiritual things that are not complex and therefore not divisible. Today we might speak of “monads” as the most fundamental units of energy.

Leibniz disagreed with Descartes that God is the mechanism that makes connection of mind-body possible. That would be to cast God as an extension of the mind and would suggest that God can be reduced to constituent parts or analyzed into simpler elements. For Leibniz, the ultimate constituents of the world must be non-material and therefore not divisible. These cannot occupy space and cannot be said to have extension. In this view, God is not a mechanism that connects things, but instead the mind that harmonizes all things. Here Leibniz approaches Baruch Spinoza’s thought. In fact, the two rationalists had spoken face to face. Spinoza conceived of God as “a being absolutely infinite, i.e., a substance consisting of an infinity of attributes, of which each one expresses an eternal and infinite essence.” Leibniz would have agreed with Spinoza’s statement that “In nature there is nothing contingent, but all things have been determined from the necessity of the divine nature to exist and produce an effect in a certain way.”

Leibniz believed that material and non-material entities do not influence one another, but there is a pre-established harmony between all entities. Consider the example of two clocks that keep perfect time and are exactly synchronized. One has a bell that rings when the hour is struck. The other has no bell; when the one clock points to the hour, the other clock rings precisely at the moment. Descartes would argue that the clocks have some connection and the mechanism that connects is God. Leibniz would argue that although the clocks have no relation to each other, they keep perfect time because from the outset they were synchronized by God.

Just as Descartes begins with skepticism to overthrow skepticism so Leibniz begins with Cartesian dualism to overthrown it with his Monism.

Related Reading: Theories of Knowledge (Part 1); Leibniz on Descartes' Principles

Wednesday, November 5, 2014

INDEX of Topics

Philosophers' Corner

INDEX (current as of 15 April 2017)

Academic Philosophy
Gender Bias in Academic Philosophy?
Beware of Letters Bearing Poop
The Dearth of Women in Philosophy
Women and Academic Philosophy
Philosophy for Primary Students?
John Haldene to Teach at Baylor University
Beware of Letters Bearing Poop
Analytic vs. Continental Philosophy

Academic Theology
Why Study Academic Theology?
Academic Theology - Crisis Magazine
Does Academic Theology Matter?
Do Academic Theologians Have to Believe in God?

A Physicist Looks at Beauty
G.K. Chesterton on Drawing the Line

Ancient Sources
Ancient Sources and Historical Reliability
Ancient Philosophers Portrayed on Byzantine Murals
African Religion Predates Hinduism
Some Marks of Prehistoric Religion
Religious Tradition
The Religion of the Saka
The Luwian: Another Theory

Reflections on the New Anglican Catechism (Introduction to the Ten Commandments)
Reflections of the New Anglican Catechism - Part 2 (The Law and Righteousness)
Reflections on the New Anglican Catechism - Part 3 (The First Commandment)
Reflections on the New Anglican Catechism - Part 4 (The Second Commandment)

Anscombe, Elizabeth
Elizabeth Anscombe
Anscombe on Justice, Sex and War

Alister McGrath on the New Atheim and New Apologetics
Williams Lane Craig on Philosophy and Apologetics
The Christian Intellectual
Reason and Revelation
St. Paul's Application of Greek Philosophy
What Christians Believe

Aquinas, Thomas
Aquinas and Motivation to Good Action
John Haldane to Teach at Baylor University

Archaic Communities/Ethics/Moral Codes/Technologies
Ancient Wisdom, Science and Technology
Ancient Moral Codes
Ethics and Archaic Communities
The Religion of Archaic Rulers
The High Places
Understanding the Axial Age

Getting Acquainted with Aristotle
Aristotle's Understanding of the Chief Good
St. Paul's Application of Greek Philosophy
Angry Birds and Aristotle

The Charitable Face of Atheism
UK Atheists and Historical Revision
More on the Humanist Anti-God Campaign

Bacon, Francis
Bacon on Atheism
Theories of Knowledge: Bacon and Descartes

Bentham, Jeremy
Thumbnail Sketch of Jeremy Bentham

Berkeley, George
George Berkeley: Idealist and Consistent Empiricist
George Berkeley A Matter of Mind

Boheme, Jacob
Jacob Boheme on Genesis

Chance, Fortune
Chance, Fortune, Determinism and Indeterminism
Machiavelli Believed in Fortune

Chesterton, G.K.
On the Corruption of Truth by Trade
G.K. Chesterton on Nietzsche
Chesterton's Philosophy of Paradox

Blind Eye or Ignorance?

Deontological Ethics
Modern Trends in Ethical Thought

Descartes, Rene
Ontology and the Philosophical Project

Derrida, Jacques
Thumbnail Sketch of Jacques Derrida
Levi-Strauss and Derrida on Binary Oppositions
Genesis and Jacques Derrida
Today's Savage Mind

Dreyfus, Hubert L.
Dreyfus on Metaphysics and Phenomenology

The Desire to Learn
Bring Philosophy to American High Schools!
Philosophy Education in France
Schools Discovering the Value of Philosophy
Why We Should Teach Philosophy in High School
Philosophy Should Be Taught With STEM
Why Logic Should Be Taught in Schools
Philosophy: The Most Impractical Practical Tool
Teaching Kids Philosophy Makes Them Smarter in Math and English

Einstein, Albert
Einstein-Bohr Debate
The Shaping of 20th Century Ethics
Einstein on the Value of Philosophy

Theories of Knowledge: Archaic Communities-Aristotle
Theories of Knowledge: Bacon and Descartes
Theories of Knowledge: Descartes, Locke and Hume
Theories of Knowledge: Hume and Kant

Moral Obligation
Revising Good and Evil
Is Bioethics a Dirty Word?
What Makes a Good Society?
Kathinka Evers on Neuroethics
Ethics and Binary Oppositions
Ethics and Archaic Communities
Ethics of Archaic Communities
Ethics of Ancient Greece
Ethical Concerns of the Middle Ages
Ethical Concerns of the Renaissance
Ethics in the Renaissance
Ethical Concerns of the Enlightenment
The Shaping of 20th Century Ethics
Modern Trends in Ethical Thought
Post-Modern Ethics

Evolutionary Theory
Random Mutations and Quantitative Analysis
Facebook Conversation on Creationism
Biblical Anthropologists Discuss Darwin

Foot, Phillipa
Thumbnail Sketch of Phillipa Foot

Jostein Gaarder 
Gaarder on Changes He'd Make to Sophie's World

Philosophers on 2016 Presidential Election

Heidegger, Martin
Heidegger on Aristotle
The Challenge of Heidegger's Terms
A Closer Look at Martin Heidegger
George Pattison on Martin Heidegger
Heidegger's Critique of Descartes

Hobbes, Thomas
Did Hobbes Change the Meaning of Justice?
Hobbes on the Order of Creation

Hume, David
Why You Have to Love David Hume
Buttiglione Responds to David Hume
Why David Hume Was Wrong
Theories of Knowledge - Part 1
Theories of Knowledge - Part 4

Husserl, Edmund
Crash Course on Phenomenology
Husserl's Critique of Descartes

The Question of Immortality

Philosophers Discuss Supreme Court Decision on Obergefell v. Hodges
Progressives Enjoy Attacking Kim Davis

Kant, Immanuel
Modern Trends in Ethical Thought
Logic: On the Lighter Side

Kierkegaard, Søren
Søren Kierkegaard
Kierkegaard: Witness to the Truth, Knight of Faith
Reflections on Søren Kierkegaard
Logic: On the lighter side
Pioneers in the Field of Logic
Why Logic Should Be Taught in Schools
Introduction to Logic: Fallacies
Modal Logic and Problem Solving
The Atheist's Fallacious Argument

Machiavelli Believed in Fortune
Ethics in the Renaissance

Meetings of the Great Minds
Fall 2014 Forum
Spring 2015 Forum

RIP René Girard
In Memory of René Girard: The Truth about Life and Death

Early Metaphysics: Primal Substance and Cause
Theories of Time
Theories of Change and Constancy
Leibniz's Modal Metaphysics
The Corporeal Universe Needs Metaphysics
Kim Davis, Metaphysics and the Public Square

Moral Codes
Menes, the Lawgiver
The Moral Code of Ani
Ancient Moral Codes

Philosophy Professors Reflect on Irrational Man

Natural Law
Natural Law: The Outside Standard
Natural Law and Justice

Nietzsche, Freidrich
G.K. Chesterton on Nietzsche
The Immortal Nietzsche
Ethics in the 20th Century
Freidrich Wilhelm Nietzsche
Reflections of Freidrich Nietzsche

The Story of Ontology
Introduction to Ontology
What Constitutes Being?

Peirce, Charles Sanders

Crash Course on Phenomenology

Why Study Philosophy?
The Most Impractical Practical Tool
What is Philosophy?
Bertrand Russell on The Value of Philosophy
University of Kentucky Philosophy Summer Camp
New Philosophy Grads Favored by Employers
Popularity of Philosophy in Germany
The Academic West Fails to Engage the East
Chinese Philosophy in the Western Classroom
When a Fundamentalist Finds Philosophy

Philosophical Theology
St. Cyril's Philosophical Theology
Wolfhart Pannenberg RIP

Plato: A Heart Fixed on Reality
Plato's Debt to Ancient Egypt
Plato on Thymos

Pragmatism and Education in America

Rand, Ayn
Thumbnail Sketch of Ayn Rand

Rawls, John B.
Thumbnail Sketch of J.B. Rawls
J.B. Rawls' "Original Position"
John B. Rawls: A Pernicious Influence?

The Philosophical Basis of Science

Austin L. Hughes, The Folly of Scientism
Scientists Against Scientism

Socrates: A man in control of himself
Ethics of Ancient Greece
Socrates' Quote

Better a Philosopher Than an Orator
Gain a Heart of Wisdom
Theories of Time
The Sun and the Sacred

Truth, Not Slogans

Virtue Ethics
Virtue Ethics

Ancient Seats of Wisdom
Ancient Wisdom, Science and Technology
Themistoclea of Delphi
The Removal of Wisdom's Tongue

Wittgenstein, Ludwig
Ludwig Wittgenstein

Women Philosophers
The Dearth of Women in Philosophy
Thumbnail Sketch of Phillipa Foot
Elizabeth Anscombe
Anscombe on Justice, Sex and War

Tuesday, November 4, 2014

George Berkeley: A Matter of Mind

Esse est percipi
To be is to be perceived.

Alice C. Linsley

George Berkeley (1685-1753) was an Irish philosopher who became the Bishop of Cloyne. He lived for a time in the American colonies where he promoted higher education. He deeded his library and his farm in Rhode Island to Yale University. One of the colleges at Yale is named after him, as is the city of Berkeley in California.

Berkeley saw a flaw in the thought of Rene Descartes who believed that objects have existence independent of our perception because they take up space, that is, they are "extended." Berkeley argued that there is no "outside" world, only the world of the Mind. Speaking of mind, many people believed that poor George had lost his! The importance of his thought was appreciated only after his death.

In his writings, Berkeley shows himself to be an consistent thinker. He argues that we cannot logically insist that objects have existence independent of human perception, that they take up space in the material sense.  This leads to the conclusion that all that exist is Mind and the content of Mind: thoughts, ideas, and perceptions. Berkeley is sometimes called an "idealist" because he believed that all things that exist are ideas.  He is also called an "immaterialist" because he denied that material objects exist. Berkeley applied this reasoning to God, saying that everything has existence in the Mind of God (panentheism).

One of Berkeley's contemporaries was Samuel Johnson, who hearing about Berkeley's theory, kicked a stone and declared, "I refute it thus."  For Johnson feeling that hard stone against his toe was sufficient evidence that the stone had material substance. However, Johnson missed Berkeley's point. Feeling the stone against your foot did not prove that the stone had extension. It only proved that the mind has an idea of a hard stone.

Berkeley develops his immaterialism in his Three Dialogues Between Hylas and Philonous (1713). The word hylas comes from the Greek word for matter, and philonous means love of Mind. In these dialogues, Berkeley shows that sensible qualities are not inherent in matter. Rather, they are ascribed and understood by the mind. Color, sound, temperature and shape are relative qualities entirely dependent on a mind. Without a mind, there is no perception of matter at all.

Berkeley sought to refute the claims of his contemporary John Locke about the nature of human perception. According to Locke, a thing's primary qualities, such as its extension, shape, motion, solidity, and number, exist apart from being perceived. Berkeley, on the other hand, insisted that primary qualities are ideas that exist in a perceiver's mind. These ideas cannot exist in an unperceiving substance.

Berkeley's method in his own words from A Treatise Concerning the Principles of Human Knowledge (1710)

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 is 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 wandered through many intricate mazes, we find ourselves just where we were, or, which is worse, sit down in a forlorn Scepticism...

My purpose therefore is, to try if I can discover what those principles are, which have introduced all that doubtfulness and uncertainty, those absurdities and contradictions into the several sects of philosophy; insomuch that the wisest men have thought our ignorance incurable, conceiving it to arise from the natural dullness and limitation of our faculties. ...

Nothing seems of more importance, towards erecting a firm system of sound and real knowledge, which may be proof against the assaults of scepticism, than to lay the beginning in a distinct explication of what is meant by thing, reality, existence: for in vain shall we dispute concerning the real existence of things, or pretend to any knowledge thereof, so long as we have not fixed the meaning of those words...

.. we are under an invincible blindness as to the true and real nature of things... Hence a great number of dark and ambiguous terms presumed to stand for abstract notions, have been introduced into metaphysics and morality, and from these have grown infinite distractions and disputes amongst the learned. 

Related reading: George Berkeley: Idealist and Consistent Empiricist; A Treatise Concerning the Principles of Human Knowledge by George Berkeley