essay by kevin freedmen
Throughout history philosophers have been trying to define knowledge, Of the necessary conditions for knowledge, Plato, Locke and other philosophers have identified a demonstrative condition, which necessitates that to truly possess knowledge of something, one must be able to explain or demonstrate (at least to oneself) how one’s reasons justify a particular belief.1
In the Theaetetus, Plato’s character Socrates begins with a claim of what knowledge is not: “[w]hen... any one forms the true opinion of anything without rational explanation, you may say that his mind is truly exercised, but has no knowledge; for he who cannot give and receive a reason for a thing, has no knowledge of that thing” (Moser and Vandernat 49). It logically follows that “when he adds rational explanation, then, he is perfected in knowledge” (49). Explanation is required for knowledge because to describe or define something separates one thing from another. Plato ends with Socrates’ statement that to possess knowledge requires true opinion as well as rational explanation (49). The demonstrative condition of knowledge requires that all of the factors needed for a particular belief to be epistemically justified for a person must be cognitively accessible to that person.
In the Meno, Plato provides a more detailed explanation of why demonstration is a necessary condition for knowledge. Socrates differentiates knowledge from true opinion: a man who possesses true opinion possesses only a correct opinion, while someone who possesses knowledge must know the truth of the matter. An example provided is that of a guide to Larisa, who “had a right opinion about the way, but had never been and did not know” (Socrates 32). Because the man would possess the right opinion of the way to Larisa he would be just as good a guide as a man who possessed actual knowledge of the way. Socrates uses this evidence to finish his explanation for why knowledge requires not only that:
S knows that P
IFF
i) P is true
and
ii) S is sure that P is true
but also that
3) S must also have the right to know P (or be able to demonstrate that P)2
Plato summarizes and completes the discussion of true opinion versus knowledge, stating that:
“while [true opinions] abide with us they are beautiful and fruitful, but they run away out of the human soul, and do not remain long, and... are not of much value until they are fastened by the tie of the cause... And this is why knowledge is more honourable and excellent than true opinion, because fastened by a chain” (Socrates 33).
Locke identifies demonstrative knowledge, saying that though agreement between thoughts or ideas may not always be intuitively blatant, it is possible that one may find connections via intermediate ideas, which one is led to by reason.3 “Those intervening ideas which serve to show the agreement of any two others, are called proofs: and where the agreement and disagreement is by this means plainly and clearly perceived, it is called demonstration; it being shown to the understanding” (Moser and Vandernat 139).
Arguably, person S needs not be able to demonstrate that P is true so long as someone demonstrates to S that P is true. This is highly debatable. Whether or not one can successfully demonstrate to oneself that P is true during a certain time period may mean that one only possesses the knowledge of P during the time in which one may demonstrate that it is true. This means that if someone demonstrates to S that P is true, but then S cannot demonstrate it themself, they no longer possess the knowledge of P, but only a true opinion of P. This would seem to show that for S to know P, S must always be capable of demonstrating P to themself.4
Since the demonstrative condition is thus far defined as a condition stating that for a person to possess knowledge, and not just true opinion, they must be able to demonstrate5 that they are justified in holding a certain belief through reason, the question of what is then excluded from the new definition of knowledge must be raised.6 The demonstrative condition excludes many types of purported “knowledge”: the first is true opinion, which is reached by luck or chance, since it cannot be demonstrated to be true by the person who has reached the conclusion by such methods; second is true opinion based on inference which cannot be demonstrated with certainty; third is abductive claims which are only inference to the best explanation; fourth is knowledge arising from experience as it consists only of belief or faith (according to Locke, and given our lack of absolute certainty of the material world’s existence we must agree); fifth type of “knowledge” excluded includes common sense or supposedly general truths; a sixth and final kind of knowledge that would be excluded would be second-hand knowledge which has been told to someone, since that person has no way of demonstrating it.
Is the demonstrative condition for knowledge too strong or not? I would argue that the line of what knowledge is and is not is a very fine one to draw, and is likely subject to opinion. It may be fair to say that we do seem to know a majority of the things we experience7, and many of our inferences may be correct, but this still makes them only true opinions. The word “know” and the phrase “to know with certainty” seem to be used so loosely in common language that they are not really true to their definitions. Although I am tempted to agree and sympathize with those who find the demonstrative condition to be too restrictive on the definition of knowledge, Plato is extremely convincing in his differentiation of true opinion from knowledge, and I think it is very difficult, if not impossible to disagree with him on the matter. One may say that (for the sake of every day usage) there are varying levels of knowledge, and that knowledge which does not meet the demonstrative condition is simply a lower class of knowledge.8
1 Demonstrative evidence, defined as a legal term may shed some light on its philosophical counterpart, as it consists of objects that may be seen or heard to give a jury a better understanding to a particular person’s argument (demonstrative evidence 1); however, there is more to the philosophical demonstrative requirement than just seeing something concerning knowledge.
2 (Moser and Vandernat 263).
3 Locke identifies four types of knowledge, one of them being demonstrative.
4 One possible objection to this may be that the argument is reduced to triviality, since one cannot constantly be in a state of demonstrating any given fact to oneself or to others, which means that according to the argument given, that one only truly possesses knowledge of something when they are in the act of demonstrating that given fact to oneself or others.
5 At least to themselves
6 Previously, from conditions (1) and (2), false opinions and non-belief or uncertain beliefs must be rejected from being knowledge. (1) could exclude experimental/scientific results because they are not certain, but this depends upon how seriously the condition is taken: does 99.9% certainty constitute “P is true”? I would venture to say it does not.
7 Or seem to experience; we are uncertain as to whether the world really is as we perceive it. See Berkeley’s A Treatise Concerning the Principles of Human Knowledge with regard to this.
8 I could accept this as a common on general definition, but not as a philosophical one. As a philosophical definition, knowledge consists of logic such as that of validly applied deduction, which should provide a person with absolute certainty if they have properly reduced all other options as to the truth of the matter.
this essay is not mine but prorty of kevin freedmen