III.2    Knowledge as Justified True Belief

There are very few human beings who receive the truth, complete and staggering, by instant illumination. Most of them acquire it fragment by fragment, on a small scale, by successive developments, cellularly, like a laborious mosaic.

                                                                Anais Nin (1903-77)

On the mountains of truth you can never climb in vain: either you will reach a point higher up today, or you will be training your powers so that you will be able to climb higher tomorrow.
Our treasure lies in the beehive of our knowledge. We are perpetually on the way thither, being by nature winged insects and honey gatherers of the mind.
All credibility, all good conscience, all evidence of truth come only from the senses.
The most common lie is that which one lies to himself; lying to others is relatively an exception.
                                              Friedrich Nietzsche (1844-1900)
 
Honesty of thought and speech and written word is a jewel, and they who curb prejudice and seek honorably to know and speak the truth are the only builders of a better life.
                                                     John Galsworthy (1867-1933)
 
A. About Knowledge in General
B. Evaluating Propositions
C. Truths and Falsity are Matters of Degree
 
A.                      About Knowledge in General
The love of truth involves the desire to have our conception of life in harmony with the actualities of life, and therefore a supreme desire to be rid of all ignorances, prejudices, and prepossessions which prevent our seeing clearly these actualities. . . . Truth is harmony of expression with reality.
                                                   Lyman Abbott (1835-1922)
  • The state of knowing does not come from simply believing something, for it must entail a justification that a belief is at least probably true. Hence, we seek Knowledge as Well-Justified, Probably True Belief.
  • Knowledge, if defined as what is claimed to be true, requires belief as a necessary condition because one can only assert to know something when one beliefs it. However, one can belief a falsehood, hence, there must be some other criteria.
  • A belief must also be justified by other necessary conditions to reduce or eliminate it being false. However, though the justification may be true with reference to itself, it may not be one that has a sufficient correlation to the belief. Thus, there must be another necessary condition.  
  • A belief must be well (skillfully, expertly) justified. That is, a belief counts as knowledge only if it was acquired by a for the context appropriate method. And by far the best and proven method or approach is the scientific one, see What is Science. However, the most important kind of knowledge, informative and predictive propositions, from the sciences are only probably true because that is the nature of empirical knowledge.
  • Hence, in the case of empirical knowledge, certainty is not possible, and it would be foolish to demand it. This kind of knowledge comes in Degrees of Truth . . . (see below). However, self-explanatory (analytic) knowledge can be absolutely true or false, but it is void of empirical content.
  • From the preceding it follows that all our decisions and actions concerning the real world are based on probable knowledge. Hence, the effort we expand to gather knowledge should be in proportion to the importance of the decision or action we contemplate. 
  • Subjective propositions that claim what is true is whatever one happens to believe are not acceptable. And the same goes for relativistic propositions that argue what is true is whatever is accepted by one's culture or community.
B. Evaluating Propositions
Propositions, statements that are either true or false, may be appraised by:
  1. The correspondence theory of truth, that is, by how they correspond to the facts of reality. For example, snow is white if and only if it is white.
  2. The coherence theory of truth, that is, by how they are consistent with the laws of physics and reason, that is, in harmony with the whole realm of rational ideas. For example, the proposition that water flows naturally uphill contradicts the law of gravity. This theory is a useful supplement to the correspondence theory because it enables us to venture with some degree of certainty into realms not subject to direct verification.
  3. The pragmatic theory of truth, that is, by how well things work. A proposition may be accepted if it leads to satisfactory results or has acceptable practical consequences. For example, some untrue belief systems, because they are neither real nor coherent, help many cope with life; hence, we should accept them. The meaning of the belief system is then in its practical consequences.
C.               Truth and Falsity are Matters of Degree
It is the mark of an educated mind never to expect more precision in the treatment of any subject than the nature of that subject permits.
                                                              Aristotle (384-322 BCE)
 
The relationship between knowledge and certainty is as follows. As the "knowledge hierarchy" below shows, only tautologies and contradictions can have an absolutely certain true or false value. Whereas, all propositions about the real world, those with an empirical content, are only probably true or false because they are contingent and never wholly true or wholly false. These predicates are a matter of probability or degree. One has to decide on a case by case basis whether or not the predicate value is acceptable or unacceptable in support of a proposition.  
6. Certainly true (a tautology)
5. Obviously true (the highest value for an empirical proposition)
4. Evidently true (next to the highest value)
3. Clearly true (in between)
2. Probably true (next to the lowest value)
1. Possibly true (the lowest value for an empirical proposition)
0. Counterbalanced (50/50)
-1. Possibly false (the lowest value for an empirical proposition)
-2. Probably false (next to the lowest value)
-3. Clearly false (in between)
-4. Evidently false (next to the highest value)
-5. Obviously false (the highest value for an empirical proposition)
-6. Certainly false (a contradiction)