III.1                   What is Knowledge?
Ignorance is the curse of God,
Knowledge the wing wherewith we fly to heaven.
                                      Shakespeare (1564-1616
 
Real knowledge is to know the extent of one's ignorance.
                                                        Confucius (ca. 551-479)

If you wish to strive for peace of soul and pleasure, then believe;
if you wish to be a devotee of truth, then inquire.
                                                      Heinrich Heine (1797-1856)
 
                          The only source of knowledge is experience.
                                                                      Albert Einstein (1879-1955)
 
Knowledge is properly understood as warrantedly assertible belief.
                                                                         John Dewey (1859-1952)
 
Introduction

Knowledge is fundamental to human life because life depends on solving problems, making sound decisions, and forming sound beliefs. What one believes about knowledge influences what one accepts as relevant evidence and therefore what one is willing to believe about particular facts and circumstances. Hence, it affects the degree or probability with which one accepts knowledge claims from sources such as the empirical sciences, reason, intuition, religion, tradition, or authority. And the degree of acceptance will influence what risks one will take in acting on this knowledge.

 
What is knowledge?
 
1. Broadly speaking, the term knowledge covers:
  • The totality of information that has been acquired thru cognition, "mental knowing" (from Latin: cogito, "to think"). Cognition is the faculty for the intelligent processing of information.
  • Understanding and integrating specific facts and concepts about some subject.
  • A collection of scientific laws that allow predictions.
  • An accumulation of information (data, facts) acquired by humankind.
2. Knowledge is the embodiment of cognition, that is, the mental process of knowing in the broadest sense, including thinking, perceiving, learning, discovering, interpreting, desiring, judging, evaluating, planning, calculating, considering, modifying, interpolating and extrapolating, awareness, intuition, critical thinking, judgment, memory, and so forth. It is, or should be, independent of whether or not it pleases humankind.
3. More specific, knowledge is what an individual believes to be true, that is, it is a highly subjective judgment. Therefore, to be intellectually honest and to convince others, knowledge requires a verifiable justification that makes the claim that it is true at least plausible (see below, Knowledge as Justified True Belief).
4. Knowledge is acquired thru direct acquaintance (experience) or description (study). So, it moves from the outside world to the mind world where it is processed. All the things people claim to know come either from their own sense perceptions or the ideas in their own minds. However, some claim that there are other sources of knowledge and that some knowledge moves from the mind world to the outside world (see Categories of Knowledge immediately below).
 
Categories of Knowledge

We must distinguish between various categories of knowledge, claims expressed as propositions. A sentence states a proposition when it asserts or denies something that could be true, false, or something in between. Moreover, the true and false values are not absolutes but often a matter of degree (see "Truths and Falsity are Matters of Degree" in Knowledge as Justified True Belief). And propositions are the subject of critical thinking, that is, the kind of thinking that goes on in evaluating their content, whether they are true or false, whether this or that is more probable.

Knowledge may be distinguished based on the nature of the source and/or evidence claimed to establish its truth or falsehood, certainty or uncertainty. Some of these distinctions were first implied by the Scottish philosopher David Hume (1711-1776).

All Knowledge propositions may be categorized by one of the following:
1. Informative (synthetic) knowledge
2. Self-explanatory (analytic) knowledge
3. Non-sensical knowledge
The three claims below may also be categorized by 1-3 above, but they require special attention:
4. Private (inner sense) knowledge claims
5. Rationalistic (mind generated) knowledge claims
6. Pseudo (false science) knowledge claims

1. Informative (synthetic) propositions are expressed by sentences:

  1. whose negation does not lead to a self-contradiction,

  2. that are a posteriori (its truth can be established only through observation, sense data),
  3. that are not true by definition, and
  4. when they are true, they are not necessarily true (they can be false).

Examples: The top of Mount Everest is 30,000 feet above sea level. Martha’s maiden name

              was Fogger.

Check: If it can be affirmed by sense data, e.g., this stone is heavy, then it is synthetic. If it cannot be affirmed, e.g., angels exist, then it is non-sensical.  

Note: These propositions tell us something new, but they are not certain and are             therefore only probably true.

2. Self-explanatory (analytic) propositions are expressed by sentences

  1. whose negation leads to a self-contradiction,

  2. that are a priori (known independently of observation), 

  3. that are true by definition, and therefore

  4. are necessarily true.

Examples: A. An unmarried man is a man who is not married (note: the concept of the

              predicate is included in the concept of the subject; hence, it is a tautology, a

              needless repetition).

              2 + 2 = 4 (four is the same as two and two).

Check: By negating the sentence. If it is self-contradictory, then the sentence is analytic but trivially adds to our knowledge base. If it is not self-contradictory, then check for informative proposition.

Note: These propositions are certainly true but lack empirical content. They tell us nothing new about the world. So certainty goes with emptiness.

3. Non-sensical propositions are expressed by sentences that are neither informative nor self-explanatory. Also, they are not verifiable by the senses--they are literally nonsense at least in a technical sense. See "Non-Sensical Assertions" in Where Thinking Goes Wrong.
Examples: Colorless green ideas sleep furiously. The Absolute rests in eternal repose.

4. Private  or subjective--inner sense--knowledge propositions are expressed by sentences that claim that there are things only known to one person in the form of a private language. Hence, the holder of a private language claims that he alone understands, but that it therefore cannot serve as a means of communication with others. However, Wittgenstein (1889-1951) in his work Philosophical Investigations (sections 243-347)asserts that this is not possible. For it must be unintelligible even to its possessor because it presupposes the possibility of private ostensive definition of something as a guide for its application, for example, decision making.

     Example:  Lets assume two people meet on a matter that requires a decision concerning moral conduct, and in this case a woman’s right or non-right over her body with respect to abortion. Moreover, lets also suppose each person claims to have a private or subjective knowledge of God that will guide them or form the basis of their decision. However, it so happens that we get two contradictory decisions, that is, one for and one against a woman’s right to an abortion. An impasse is reached because neither party can objectify its grounds for a fruitful discussion.

5. Rationalistic--mind generated--knowledge propositions are expressed by sentences that assert information that comes from the intellect in itself without aid from the senses or experiences. This is possible as in the case of mathematics and logic, and it has the highest degree of certainty. However, this info is empty, for it can tell us nothing about the real world.

6. Pseudo-knowledge or pseudo-scientific* propositions are expressed by sentences that claim a body of knowledge, methodology, belief, or practice that is claimed to be scientific or made to appear scientific but does not meet scientific criteria. These propositions lack plausible supporting evidence; hence, they are not scientific claims. These pseudo-knowledge declarations are often harmful and should therefore be demystified or debunked.

*The term comes from the Greek root pseudo- (false or pretending) and "science" (from Latin scientia, meaning "knowledge").