What IS Knowledge?

What is Knowledge?

Knowledge is a type of belief—which means that it involves concepts and abstractions in our brains. As such, the most basic prerequisite for knowledge is the existence of a conscious, living being. As best as can be determined, knowledge cannot be achieved outside of living beings which are conscious at least some of the time. Two other characteristics appear vital: those of acquisition and verification. Since knowledge exists as abstractions, it must be abstracted from something—so knowledge is something we acquire over time rather than are simply born with. In this way knowledge is distinguished from instinct and instinctual actions.

I Know

A common philosophical definition of knowledge is a justified true belief. What this means is that for any belief to qualify as knowledge, you must (1) be justified in believing it, and (2) it must actually be a true proposition.

If you believe that all crows are black without ever having any experience with crows or birds, then that belief does not qualify as knowledge. It may be true but you weren't rationally justified in believing it.

Similarly, if you believe that all dogs are large because you have never encountered a small dog, that also would not qualify as knowledge. The belief may have some reasonable justification, but the claim simply isn't true. Verification is the process by which we make sure that what hear has some basis in truth. This is vital because we are fallible—it isn't true that any idea which occurs to us or which we can conceive is correct. Since it makes no sense to say that a person knows something which is false (i.e., that 2 + 2 = 5), we must make some effort to verify information before being able to properly say that we know it.

Epistemology, or the study of knowledge, has focused on the problem of justification: precisely what, if anything, can constitute adequate justification for knowledge? One debate is between rationalists and empiricists who disagree about the sources which might provide evidence. Another debate occurs over the question of certainty, with fallibilists and skeptics doubting that certainty can be achieved.

The question of knowledge also has implications for the philosophy of the mind. If someone can be said to have knowledge, then it also follows that they must have a mind—thus, understanding knowledge can lead to understanding about the mind. Is knowledge contained in the physical brain, or is it held by some other, non-material entity labeled "mind"?

There are also three general categories of knowledge which should be distinguished:

  1. Factual or Propositional Knowledge: this is when we make statements which are factually correct. For example: I know that Germany, France, England, Russia, and Italy, all fought in World War II. [NOTE: Epistemological concerns deal with how you have come to determine this as a fact of knowledge and not merely as an untested belief. How do you know it?]
  2. Procedural Knowledge: this is when we know how to go about doing something. Examples would include gymnastics or juggling—and these point out that procedural knowledge involves more than reading a book. Reading about how to juggle is not the same as actually being able to do it. When someone claims to know how to juggle, we assume that they can actually perform the act rather than that they've merely read an instruction manual.
  3. Knowledge of Personal Experience: this is the type that is meant when someone says "I know war" or "I know pain." In these instances, the person can draw upon personal experiences not otherwise available to others.

What is Epistemology?

Epistemology is the investigation into the grounds and nature of knowledge itself. Epistemological studies are usually focused upon our means for acquiring knowledge, and as a consequence, modern epistemology generally involves a debate between rationalism and empiricism, or the question of whether knowledge can be acquired a priori or a posteriori:

  • Empiricism: knowledge is obtained through experience.
  • Rationalism: knowledge can be acquired through the use of reason.

According to empiricism, we can only know things after we have had the relevant experience—this is labeled a posteriori knowledge because posteriori means "after." According to rationalism, it is possible to know things before we have had experiences—this is known as a priori knowledge because priori means "before."

First, it should be noted that empiricism and rationalism exhaust all possibilities - either knowledge can only be acquired after experience or it is possible to acquire at least some knowledge before experience. There are no third options here (except, perhaps, for the skeptical position that no knowledge is possible at all and by any means); this means that everyone is either a rationalist or an empiricist when it comes to their theory of knowledge.

Rationalism, however, is not a uniform position. Some rationalists will simply argue that some truths about reality can be discovered through pure reason and thought (examples include truths of mathematics, geometry and sometimes morality) while many other truths do indeed require experience. Other rationalists will go further and argue that all truths about reality must in some way be acquired through reason, normally because our sense organs are unable to directly experience outside reality at all.

Empiricism, on the other hand, is more uniform in the sense that it denies that any form of rationalism is true or possible. Empiricists may disagree on just how we acquire knowledge through experience and in what sense our experiences give us access to outside reality; nevertheless, they all agree that knowledge requires experience.

Althoughugh empiricism and rationalism exhaust the possible options for how we acquire knowledge, that isn't the full extent of epistemology. This field also addresses questions about how we construct concepts in our minds, the nature of knowledge itself, the relationship between what we "know" and the objects of our knowledge, the reliability of our senses, and more.

So why is epistemology important? Althoughugh it may sound rather esoteric, epistemology is important because it is fundamental to the way in which we think. Without some means of understanding how we acquire knowledge, of underststanding how we rely upon our senses, and how we develop concepts in our minds, we simply have no coherent path for our thinking. Thus, a sound epistemology is necessary for the existence of sound thinking and reasoning—this is why so much of philosophical literature can be taken up by seemingly arcane discussions about the nature of knowledge. Without recognizing and researching epistemology or considering how we as individuals acquire knowledge and what such knowledge 'means', we are merely making belief assumptions not based on anything at all, neither sound thinking, critical analysis, practical reasoning, or dedicated research. In other words, without taking knowledge seriously, without endeavering to sort out all the epistemological questions, we are not basing our belief assumptions on any real knowledge but only upon our own subjective beliefs which may be motivated by anything but the acquisition of knowledge (i.e., justified true beliefs).

The basic questions asked in epistemology include:

What can we know?

  • How can we know it?
  • Why do we know some things, but not others?
  • How do we acquire knowledge?
  • Is knowledge possible?
  • Can knowledge be certain?
  • When is knowledge true?
  • Are beliefs ever knowledge or does knowledge preclude beliefs?
  • If not knowledge, what basis or what proofs do I have for my beliefs?
  • Are my beliefs rational and based on sound evidence or something else?
  • When can I know that my beliefs are true and if I cannot than why do I presume to call this knowledge?
  • Is knowledge justified true belief or is there an element missing in that definition (e.g., 'undefeated')
  • What is the Gettier Problem? Is there a solution to the gettier Problem?
  • What is Scepticism?
  • What is Cartesian Certainty and Foundationalism?
  • What is Reliabilism?
How then are we placed with respect to the veridicity of our beliefs? Each of us, in his own given situation, has to do his (her) best to shape and reshape critically his (her) own beliefs in the light of what, in all conscience, (s)he takes to be relevant and sufficient evidence. There are no exact rules for doing this; each area of knowledge, like each field of practical skill, has its own procedures, which the learner has to interiorize first as apprentice and then as discoverer. That there are no exact rules for acquiring knowledge, however, does not mean that the whole matter is arbitrary or subjective; far from it. Objectivity—the contrary of subjectivity—is not something somewhere totally detached from human practice: it is the supreme virtue of all the cognitive disciplines. But a virtue is a developed human capacity: in this case, the developed capacity to make judgments in accordance with the evidence. Again, there is no formula for doing this, although those philosophers and cyberneticists whom I have christened algorithmaniacs may (falsely) believe there is. Through the concepts and judgments and techniques appropriate to a given discipline or sphere of life, one does one's best, in Polanyi's phrase, to make contact with reality. One may succeed or fail. In the light of the growth of scientific and historical knowledge, it seems only reasonable to assert that success is fairly common, if never total. One can never know, in the old-fashioned sense of 'know', that this is so; but one has very good reason to hope it is. We count as knowledge, then, such beliefs as we hold, in good conscience, to be justified. Knowledge is justified belief.

Then what happens to the veridicity of knowledge? Did Newton know there was absolute, true, and mathematical space, while: we, since Einstein, know there isn't? Again, this is where the crunch comes, but it's the crunch we're in and we can face it (or whatever one does with a crunch) without falling back into scepticism. If I assert that I know p, or confidently assert p, which comes to the same thing, I do so correctly only if p is in fact the case. 'p' is true if and only if p. Fair enough. And when, from my limited point of view, I assert p as an item of knowledge, following as best I can the available evidence, I do assert it as true—as universally true. And yet I can't be logically certain; I might always be mistaken. What I am doing is to assert a given proposition, as Polanyi put it, with universal intent, in confidence that anyone with the same evidence and the same standard of objectivity would make the same assertion—and would be correct in doing so. But this is always an intent, not a guaranteed fulfillment.

Then what about our earlier remark that knowledge is a 'success' word? We have two choices here. We can say we often have good reason to hope we know, and so are justified in claiming to know, although we may be mistaken. So we count our justified beliefs as knowledge, even while reserving the possibility of error. To say I know is to make a reasonable claim to success, not to guarantee it. Or we could say, somewhat more conservatively, that we believe we know a good deal—we could assert confidently that many of our beliefs are true—but that this meta-belief, that we know a good deal, cannot be definitively vindicated once and for all. So we know that we know only in the sense of holding a justified belief. I'm not sure there's very much to choose between these two formulations. I do somewhat prefer the former, which straightforwardly equates knowledge with justified beliefs, beliefs we have reason to hope are true, instead of sidestepping fallibility by a shifting of logical levels. Either formulation unsettles in some way the foundation of knowledge in truth. Either formulation, on the other hand, allows us to include scientific knowledge in knowledge and that, it seems to me, is an advantage. None of the other three answers to the knowledge-belief question allows us to do this, the first because it is after an infallible knowledge quite different from anything claimed by science, the second because it denies the existence of any knowledge at all, and the third because there seems to be no satisfactory way to cash out 'truth' in the justified-true-belief formula. So it's the fourth answer we're left with. It's a somewhat uncomfortable answer—but, despite Boethius, philosophy has seldom, when awake, been a comforting subject.

From: Marjorie Grene, A Philosophical Testament, pp. 18-20.


What is called "knowledge" can be either practical or propositional. Practical knowledge is 'knowledge-how', whereas propositional knowledge is 'knowledge-that'. In the context of the concept of truth we shall only be concerned with propositional knowledge. In a broad sense a theory of truth should include a theory of (propositional) knowledge of what is true, or a theory of what we know to be true. Similarly, a theory of relevancy should include a theory of (propositional) knowledge of what is relevant, that is, of what we know to be relevant; and a theory of property a theory of (propositional) knowledge of what is someone's property, that is, of what we know to be someone's property. Whether a theory of knowledge of what is relevant, and of what is property, is simply part of a theory of knowledge of what is true is itself an issue for those theories.

Propositional knowledge is true belief, but true belief need not be knowledge, because a belief may just happen to be true. If someone believes that it will rain at a particular moment in the future, and it does indeed rain at that moment, his-or-her belief is not knowledge or has not been knowledge for that reason. What distinguishes such a lucky guess (if it is one) from knowledge is at least justification, epistemic justification to be precise. But even this standard definition of knowledge as justified true belief has been attacked for being too simple. Traditionally its criterions are: (1) p is true; (2) S believes that p; and (3) S's belief that p is justified. It has been argued that these three criterions are minimal ones, and that S should also not believe that p, if p is not true. Moreover, S should indeed believe that p, if p is true. On such a conception of knowledge it is said to 'track', as it were, the truth that p. For our present purpose, however, it is not necessary to consider such additional criterions. The first step, that is, the one from true belief to justified or grounded true belief is the most important one for us here.

The central problem for those interested in theory of knowledge is, of course, whether something can ever be known for sure, and if so, how. If something cannot be known for sure, the problem is whether one can still be justified in considering something true nonetheless. Extreme skepticists would say that one cannot know anything for sure. They doubt everything. Dogmatists, on the other hand, claim knowledge without ever seriously and honestly examining what their claims are based upon. They do not doubt their 'truths' which they may readily call "self-evident truths" or "revelations". (Such 'truths' which are mere products of belief we shall henceforth call "doxastic truths". As a product of belief a doxastic truth need not be false: it may happen to be true.)

Skepticism admits of degrees. A skepticist may only doubt certain kinds of belief, or specific opinions regarded as knowledge by others. He-or-she may be skeptical about the 'apriori intuition' or 'knowledge' of a rationalist, but also about the 'empirical intuition' or 'knowledge' of an empiricist. Rationalism in the epistemological sense, or apriorism, is, then, the view that there is knowledge which does not depend on experience for its justification, knowledge which can be derived from 'self-evident' axioms or principles by deduction. It is also called "rationalism", because this knowledge is said to come from reason or from ideas the mind would be endowed with independently of any experience. The complement of apriorism, empiricism, is the view that all knowledge depends on experience for its justification. Sense perception and introspection are the sources of empirical knowledge which can be derived from those sources by induction.

Both apriorists and empiricists may consider themselves skepticists, or may start as such, the former ones with regard to empirical knowledge, the latter ones with regard to apriori knowledge. The apriorist may show how people can be deceived by their senses, and tell us that we cannot be certain that this does not happen all the time. The by now worn-out standard example is that of a stick partially immersed in water which seems to be crooked when looking at it, but which turns out to be straight when feeling it. (Note that we can only be sure that we are deceived visually here, if we assume that our sense of touch does not deceive us.)

The empiricist on his or her part can easily point at the many apriorist beliefs which have once been presented as 'indubitable truths', but which are now controversial or acknowledged to be false. Thus for apriorists it was once self-evident that one, and only one, line could be drawn parallel to another line thru a given point, that—what has later been denied by mathematicians believing in the existence of infinite sets—a whole is greater than any of its parts, that in all change of the material world the quantity of matter remains unchanged (not 'of matter and/or energy'), and so on and so forth. (One idealist who tried to synthesize rationalism and empiricism said that the laws of science are not drawn from nature, but prescribed to it.)

The most egregious historical example of 'skeptical rationalism' is that of a philosopher who purported to doubt everything, but who, all the same, maintained that he/she had a 'clear and distinct' conception of one 'supremely perfect god'. It is in such monotheist dogmatism that 'skeptical rationalism' and 'empiricism' even used to meet each other, for also empiricists once claimed to have 'demonstrative knowledge of God's existence'. Although their 'knowledge' was not apriori but empirical, the ideological result was the same, and had to be the same to start with. (It would of course have been equally dogmatical to claim that apriori intuition or empirical evidence would prove that there is not any god or demon.) One would expect that the end of this theist dogmatism was in sight when, with the synthesis of rationalism and empiricism, it was argued that the supernatural entities to which concepts like god, demon and immortality refer were beyond all possible experience, and could therefore never be objects of knowledge. What does the trick in this case tho, is a marked contrast between knowledge and faith, and the possibility not only of justified knowledge but also of justified faith which is not knowledge. (Faith in immortality but somehow not in preexistence, for instance.)

When hearing or reading the word faith one should bear in mind that this word is used in several senses. Three forms of faith which have been distinguished are: faith in spite of evidence to the contrary, in the absence of such evidence, and on account of evidence. Now, when contrasted with knowledge, faith means ungrounded belief so far as evidence is concerned, that is, faith in the absence of (and possibly in spite of) evidence to the contrary. But why would we have to have faith that there is at least one god, and that 'man' is immortal? According to one monotheist philosopher and ideologue, because 'man's nature demands it', because 'man is not merely an animal that knows but one that acts and feels'. One must have faith in this sort of reasoning to consider it as reasoning in the first place.

Another philosopher of later times has also admitted that there is no scientific evidence for or against the existence of gods or immortality, yet the justification of the belief in one or more gods, and the belief in immortality, is according to him that such beliefs are 'the deepest cravings of man'. Without them people's moral standards would collapse. On the pragmatist outlook of this philosopher—or should we say "ideologue" again?—there is said to be a close connection between what is good and what is true. However, the close connection is not really between what is true and what is good, but rather between what is believed to be true and what is believed to be good by adherents of the same ideology, in this case of the same monotheist religion. If the right to believe something is indeed determined by the will to believe something in the absence of evidence, if not in spite of evidence to the contrary, then the right to disbelieve something is equally determined by the will to disbelieve something. The 'deepest craving' of some people may be a belief in gods, demons and immortality, yet the 'deepest craving' of other people is a belief in a conceptual austerity which does not allow for notions like god, demon (or names like God or Devil) and immortality. And while one group of people may defend the existence of one or more gods and immortality on the basis of their system of norms and values, other persons may reject the belief in the normative supremeness of such a god, or such gods, and/or in immortality on the basis of a different system of norms and values. (The very fact that they reject something on principle presupposes and requires moral standards.) Thus the pragmatist theory of truth is an instrument which merely 'justifies' opportunism.

The idealist distinction between knowledge and faith is itself not justifiable, for given that knowledge is grounded belief and given that it need not always be based on empirical evidence (although it may never be contrary to it), there is no place for faith in the religious, that is, supernaturalist, sense. It is precisely religious faith and religious authority which have always been the pillars of denominational dogmatism. And it is in turn this religious dogmatism which has historically been most inimical to the advance of scientific knowledge, at least until its role was taken over by other forms of ideological dogmatism in politically totalitarian countries. If one can just take anything for gospel and present it as absolute, indubitable or infallible 'truth', this has nothing to do with knowledge or justification anymore. To call one's belief in such gospel 'truth' "religious science" or "(mono)theist science" or something similar with "-ology"—as has been done—is, then, the ultimate corruption of language and a travesty of truth itself.

From: http://www.trinp.org/MNI/BoI/4/3/1.HTM

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LAST UPDATED: March 19, 2006
March 19, 2006