Monday, 6 February 2017

The Great Ideas ~ The Difference Between Knowledge and Opinion

The Difference Between Knowledge and Opinion

When considering the distinction between knowledge and opinion there are some questions that need investigation:

  1. What sort of objects are the objects of knowledge, as opposed to the objects about which we can only have opinion?
  2. What is the psychological difference between knowing and opining as acts of the mind?
  3. Can we have knowledge and opinion about one and the same thing?
  4. What is the scope of knowledge?  How much knowledge do we really have as opposed to the kinds of things about which we can only have opinions?  What is the limit or scope of opinion in the things of our mind?

Luckman begs another question to Adler: Does freedom of conscience give a person a right to his own opinion in matters of religion and, if so, are matters of religious belief and religious faith simply matters of opinion rather than knowledge?  Adler responds that this question is contained in the fourth question, as we try to separate the "sphere" of knowledge from the "sphere" of opinion.

Before he begins, Adler investigates the difference between knowledge and "right opinion".  With knowledge, you have the truth and know that it is true.  With right opinion, you have the truth but you will not understand why it is true.

Public Opinion
George Bernard O'Neill
source ArtUK

It's Better To Be Ignorant Than Wrong

Adler introduces the terms error and ignorance.  In both cases, the person will not have the truth; then how is each term different?  The person in error does not have the truth but does not know that he does not know the truth and, in fact, might think that he has it; whereas the person in ignorance does not have the truth and knows that he does not have it.  Knowledge and right opnion (on the side of truth) are mirror images to ignorance and error (on the side of lack of truth).

Therefore, ignorance is closer to knowledge than error.  In fact, to impart knowledge, one must first correct error to get the person in a state of ignorance so they can then begin to learn.  This method was Socrates' principle of teaching.  He would go around "cross-examining the pretenders to knowledge and wisdom," and by this method demonstrate their errors.

Virtue and Nobility Putting
Ignorance to Flight (c. 1743)
Giovanni Battista Tiepolo
source ArtUK

School Children Mainly Learn Opinions

Ooo hoo!  This should be a good one!

The Greeks were very concerned about the difference between knowledge and opinion. Plato believed that only knowledge is teachable; right opinion was not teachable because it was not established on reason, and since it had no principles, there was no basis for anything to be demonstrated.

Most of the subjects that children learn in school are right opnion, such as history, geography, etc., compared to geometry which can be rationally taught and learned, and outcomes can be proven based on principles.

Aristotle, however, felt that one man can opine that which the other man knows, one possessing right opinion and the other knowledge about the same thing.  For example, a teacher teaching geometry knows the truth of the Pythagorean Theorem because he has seen the conclusion demonstrated but a student who can only say that it's true because his teacher said so, only has right opinion of it on the authority of the teacher.

Anyone who argues from authority, holding an opinion or position, he is holding it as a matter of opinion.  (Hold on to your hats for this next quote:)
"And whenever a teacher appeals to his authority to persuade the students to believe something, that teacher isn't teaching; he's really only indoctrinating them; he is forming right opinions in their minds."
Luckman wonders how much, if any knowledge is taught in schools and if it's even possible to attain knowledge in these institutions.  Alder, while acknowledging that it's a difficult question, promises to address it by dividing the domain of knowledge from that of opinion.

A School Teacher Explains (1516)
Hans Holbein the Younger
source Wikiart

Opinions Are Accepted Voluntarily

How do we determine the difference between the act of knowing and that of opining? When our compliance is involuntary, caused by the object about which we're thinking, is knowledge; for example, if someone holds up two apples and then another two apples you are compelled to acknowledge that 2+2=4.  An opinion leaves you free to make up your mind based on authority, your interests, your emotions, your passions, etc. Your opinion is an act of will, which Adler calls wishful thinking, and the emotional content is great; with lack of evidence of facts, one tends to support our opinions with emotions. Adler states schools may teach opinions but they must be substantiated and tested without merely relying on authority or knowledge.  Luckman wants to know of what is taught in school, how much is knowledge and how much is highly probably opinion.

Skeptics Deny That We Have Knowledge

Adler responds to Luckman's question, asserting that there are two answers, one given by the skeptic and the other given by the opponent to the skeptic.  The skeptic believes that we have almost no knowledge, the opponent that we have substantially more knowledge.

The Skeptic

Michel Montaigne represent an extreme of skepticism, stating that everything is a matter of opinion and that man knows nothing.  The illusions of the senses cause us to think we know when in fact, "... we mustn't be fooled by the feelings which we sometimes have of certainty."  David Hume exhibits a more moderate skepticism, stating that we do have some knowledge, but it is knowledge based on science and mathematics.  Hume believes that this is the only knowledge of which we're in possession.  Hume's famous statement sums up his beliefs:

"If we take in our hand any volume ..... let us ask 'Does it contain any abstract reasoning concerning quantity or number?', that is, is it a work in mathematics?  Or let us ask, 'Does it contain any experimental reasoning concerning matters of fact and existence?', that is, is it a work in experimental science?  If the answer to both these questions is no, Hume says, 'Commit it then to the flames: for it can contain nothing but sophistry and illusion."

In modern times, we have descended even further into scepticism than Hume.  We question if even mathematics is knowledge based on Euclidean and non-Euclidean geometry.

Life's Illusions (1849)
George Frederick Watts
source Wikiart

Answer To The Skeptic

(ooo, this is good)

Adler first looks at perceptual illusion.  How do we know that there are illusions?  We can only know something as an illusion if "we regard some sense perceptions as accurate," otherwise we couldn't categorize others as illusions.  If there are two lines on a paper that look different lengths, but we pick up a ruler and measure each finding that they are the same, we correct an illusory perception.  But if one sees the measurement itself as a perception and not as knowledge, one couldn't have called the wrong perception an illusion.

With regard to mathematics, the opponent could say that "mathematics is not based only on assumptions but upon axioms, self-evident truths," as are metaphysics and other branches of philosophical science.

History and experimental science likely fall under the label of highly probable opinion, so perhaps in this case the skeptic and his opponent are in agreement, however experimental science is a type of conditional knowledge, "conditional upon the state of the evidence at a given time."

One last reply to the skeptic is given, Adler pointing out that even if the extreme skeptic tried to defend his case, he would defeat himself every time because he could not make an argument that did not establish something as knowledge.

Religio and Fides (Religion and Faith) [1575-77]
Paolo Vernese
source Wikart

Is Religion A Matter of Opinion?

Luckman still would like Adler to address if religion and matters of faith are knowledge or opinion.  Adler says there are two views of religious faith:

  1. William James asserted that "religious faith is an act of the will to believe and this act of the will to believe takes place when we are beyond the evidence or the evidence is insufficient."  James believed that faith was strictly opinion.
  2. Thomas Aquinas believed, as James, that faith is an act of will, but unlike James, believed it is an act of will motivated by "the supernatural gift of the grace of God."  For Aquinas, faith wasn't knowledge or opinion but somewhere in between.

To expand, Adler quotes Aquinas:

"The intellect assents to a thing in two ways: first, through being moved to assent by its very object which is known either by itself as in the case of first principles or axioms or through something else already known as in the case of demonstrating conclusions.  In either case, you have knowledge, not opinion.  Secondly, the intellect assents to something not through being sufficiently moved to assent by its proper object, but through an act of choice, whereby it voluntarily turns to one side rather than the other."

If doubt or fear accompany the experience, you have opinion, but if certainly follows, one has faith.  Aquinas continues:  "And this certainty of faith, results from the fact that it is supernatural," this gift from God, "since man, by assenting to maters of faith, is raised above his nature, this must needs accrue to him for some supernatural principle, moving him inwardly, and this is God.  Therefore faith, as regard to the assent which is the chief act of faith, is from God, moving man inwardly by grace."

Luckman doesn't see how Aquinas has proven faith is intermediary, between both knowledge and opinion, rather like both of them, and Adler expands.  Faith is like opinion because it is an act of will ("Now faith is the substance of things hoped for, the evidence of things not seen."  Hebrews 11:1 NKJV), but it is also knowledge, in that there is a certainty that is even greater than the certainty of ordinary knowledge, but this certainty is based on the supernatural gift of grace.

Next Adler will investigate the problems of opinion in relation to human freedom in Opinion and Human Freedom.

⇐ How To Think About Opinion                              Opinion and Human Freedom ⇒


  1. Great post. I read this when you posted it on Monday but haven't come back to comment.
    Not much to say really, but since there is no "like" button, my "great post" is a verbal "like". As long as you can stomach all the quotes :-)

    1. Thanks for the like, and the like, and the like ...... Gee, it sounds like it should be put to music! ;-)