Part 3: The Nature of Knowledge: The Problem of Knowledge, Universal Skepticism, A Realistic Theory of Knowledge

By Jonathan Dolhenty, Ph.D.


A Brief Introduction to Epistemology


The Problem of Knowledge

The ordinary person does not question that he has spontaneous convictions such as those described above. All philosophers admit that man has these experiences, considered as subjective states and that man is subjectively convinced that these experiences reveal to him an objectively existing outside world.

There is, however, according to philosophers and would-be philosophers, a vast difference between these experiences as such and the interpretations man makes of them. Whether the physical world as real actually corresponds to the world as perceived is the fundamental epistemological question.

Again, philosophers admit spontaneous convictions as subjective facts. But they contend that these convictions, as interpretations of reality, must be validated. There is good reason for this concern.

Many spontaneous convictions have been proved to be wrong, such as the conviction that the sun moves around the earth or that the earth is flat. The belief that gases, fluids and solids were bodies consisting of homogeneous material is now known to be false. Instead they are chemical compounds of very divergent elements united in definite quantities and so forth. The bent stick in the water is another example of a spontaneous conviction which raises doubt about true knowledge.

A Statement of the Problem

The general problem of knowledge, then, can be stated this way: Have our spontaneous convictions a rational foundation, so that they are based on impressions derived from reality and actually give us knowledge of reality as it is in itself?

Universal Skepticism

Universal skepticism denies the possibility of achieving certitude. Knowledge as such is not possible. An absolute skeptic would say we can’t even a justified opinion about reality. Other skeptics may not argue from an absolutist position but may argue that we can only have probable knowledge, which means we would never know whether a proposition was really true or false.

Skeptics present the following arguments to justify their case:

(1) Our faculties often deceive us. Our experience itself shows this fact. We may see a thing when in fact we do not see it. We may make a judgment that something is the case when in fact it is not. We are fooled many times by our senses, such as the “bent” stick in the water. The quest for truth is in vain. We must remain in ignorance, or at least in doubt.

(2) We may be the victim of a Power who delights in fooling us, watching us milling around hopelessly in tangles of doubt and error. We cannot know whether this is a fact, but as long as it is possible, we have to remain skeptical.

(3) We must have proof or evidence to know a thing is true. But then we must also have proof or evidence that the proof or evidence is reliable. And then we must have proof for this proof. And so on we go endlessly. But this cannot be so; we cannot go on endlessly. There must be some solid ground upon which evidence and proof must rest. The skeptic, however, says there cannot be such a starting-point and, therefore, we cannot achieve certitude.

Before we take each of the above arguments in turn, let’s consider some very obvious facts:

(1) The defender of skepticism asks us to accept his argument that it is certain that there is no certitude. A simple contradiction.

(2) The defender of skepticism offers evidence for his argument while denying the value of all evidence. A simple contradiction.

(3) The defender of skepticism uses the mind to work out the argument that there is no use using the mind at all. A simple contradiction.

Such is the dilemma of the true skeptic. He continually contradicts himself. A real skeptic has only one choice: to remain silent. The second he opens his mouth, he declares as true certain facts:

  • He exists;
  • He knows he exists;
  • He has certain knowledge of the doctrine of skepticism he holds;
  • He knows other people must exist to listen to him; and
  • He knows they must have minds which may be influenced by his doctrine of skepticism.

The genuine skeptic, then, cannot speak at all without contradicting himself. There are only two positions that can be held in regard to certitude. Either we can know truth or we cannot know truth. If we can know truth, then we can enter into an investigation of what constitutes truth and how we may attain it. If we cannot know truth, then we stop, all conversation ends, and we are forever condemned to ignorance or complete doubt about everything. This philosophy cannot be lived in the real world.

This should be enough to show that skepticism is both a theoretical and practical impossibility. But, for the sake of the discussion, let’s consider each of the arguments in defense of universal skepticism.

(1) The skeptic says our senses or our intellect deceive us. He is dead wrong. Used correctly, our senses and our intellect are infallible. When we are deceived, it is because we make a rash judgment without waiting for adequate evidence, or we use our senses or our intellect for purposes the senses and the intellect were not meant to serve, or we fail to make, particularly in the case of our senses, allowances for organic defects, or we fail to consider the conditions under which our senses or our intellect should operate.

Our faculties of sense and intellect do not deceive us, but we frequently misuse them.

Let’s look at the famous “bent” stick in the water example. What our eyes actually see is, of course, a “bent” stick. Our eyes are not deceiving us at all. The stick indeed appears to be bent. The error comes in when our intellect makes the judgment, “The stick is bent.” Now, our intellect is not deceiving us. Our judgment is simply wrong because we have not considered all the facts of the matter, that is, we are making a judgment based on incomplete evidence.

I now put my hand in the water and touch the stick. I find out that the stick is not really bent at all. Why, then, does it appear bent? Eventually I find out the effect that light has in water and determine that the stick only appears bent because of this effect. My intellect can now make a correct judgment, one without error: “The stick is not really bent, it just appears bent to my eyes because of the effect that light has in water.” No deception has taken place at all.

Again, a judgment can be in error for a number of reasons. We may judge rashly. We may not wait to test conclusions. We may not know all the facts of a situation. We haven’t waited until all the evidence is in. We allow our emotions to cloud our judgment. We may not properly evaluate the evidence sent to us by our external senses. But the fact still remains: Our senses and our intellect do not deceive us. Any deception is in the judgment we make. It is our fault, not that of our senses or our intellect.

Universal skepticism fails to make its case.

(2) Perhaps we are at the mercy of a Power who delights in deceiving us. The answer to one “perhaps” is another “perhaps.” So, perhaps not are we at the mercy of such a Power. There is certainly no evidence that we are. And, furthermore, why should such a Power give us such complex sense-organs and such a powerful intellect if all that Power wanted to do was fool us?

Besides, our senses and our intellect serve us quite well in our everyday lives. Farmers are certain that nature is constant and they plant their crops in spring and summer, only to harvest them in the fall, and this goes on year in and year out with very little deviation. When the farmer plants wheat, he is confident it is wheat that will grow and be harvested and it won’t turn out to be a field of watermelons.

Just on practical principles alone, universal skepticism fails to make its case.

(3) An endless series of proofs to establish certitude? This, of course, is ridiculous. There are certain primary truths, self-evident truths, which even the skeptic must accept because to deny them is to end up in self-contradiction. The skeptic must accept his own existence or he must simply shut up, crawl away, and forever remain silent. After all, how can the skeptic say “I doubt if I exist”? What does the “I” refer to? Nothing?

The primary truths, which will be discussed later, are self-evident truths which cannot be proved because they contain within themselves the proof of their own truth. These truths are the solid ground upon which all knowledge rests. There is no need for an endless series of proofs.

 A Realistic Theory of Knowledge

A realistic theory of knowledge squares with what our common sense, critically examined, tells us. Our minds are capable of obtaining truth with certitude. A real, material, physical, objective, world exists outside of our minds, a world we do not make or construct. And we can obtain knowledge about this world.

Our minds are capable of recognizing certain self-evident truths which we can assert with absolute certitude. We can build upon them to attain a body of knowledge that is certainly true. The mind can investigate, looking for evidence, and make judgments about the world of external reality.

Physical, external objects are presented directly in some form to our consciousness in sense-perception. The reality of these things is perceived as it exists “out there” in nature. The objects are presented directly to our minds through the medium of the senses, and the object itself is immediately the object which is perceived.

Properly used, our senses are infallible. Our senses are properly used when, and only when, the following requirements are observed:

  • A sense must be employed upon its proper object. The object of the eye is color. The object of the ear is sound. The object of the taste buds is flavor. The object of the olfactory senses is odor.
  • A sense organ must be sound and not defective. A person who is deaf will not hear sound. A person who is color-blind will not see certain colors in a normal way.
  • The medium in which the sense organ is used must be suitable to the sense organ. Human beings do not normally smell objects while under water. Human beings do not normally see color in complete darkness.
  • The proper object itself must be presented to the sense organ so it lies within the normal range of that organ’s activity. Human ears, for instance, normally have a limited range for perceiving sound. Dogs are capable of hearing sounds above the normal human range.
  • The sense organ must be given sufficient time for its normal function. The success of a magician often depends on the fact that human eyes need sufficient time to see what they see. The fact that “the hand is faster than the eye” does not mean the eye is defective. The eye simply has not had sufficient time to do its job.

Our senses do not deceive us. All human knowledge acquired in this life begins with the action of the external senses and it is upon this that the ultimate foundation of human knowledge rests. If this foundation is insecure, then no human knowledge is reliable and we are compelled to skepticism forever. As we have seen, this virtually makes life impossible.

Our sense organs are reliable. The senses, properly used in accordance with the requirements listed above, give us a knowledge of reality. As a result, our senses can be the source of valid evidence and any error we may make can be explained as an error of judgment and not an error of the senses. Our errors of judgment may be caused by lack of sufficient evidence, pseudo-evidence improperly obtained, or lack of proper attention on the part of our intellect.

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The late Dr. Jonathan Dolhenty was the Founder and President of The Center for Applied Philosophy and the Radical Academy, and is Honorary Philosophy Editor at Self-Educated American. Self-Educated American has adopted these projects beginning with a republishing and preserving of all of Dr. Dolhenty’s work.

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