Excerpt from How to Think about Truth by Mortimer Adler

Truth is connected with the pursuit of knowledge. Because the very meaning of the phrase “to know” is to have in one’s mind the truth about the object one is trying to know. To know is to have the truth.

To know something is to doubt

(1) The skeptic thinks that there is nothing true or false, or that everything is equally true and false and that we are unable to know what is true or what is false, that we simply don’t have knowledge or possess the truth.

Truth is dependent on the person.

(1) Another attitude toward truth is relativism. And according to this view, some things that are true for you are false for me, and what may be true for me is false for you, and what was once true in some other period of history or in some other culture is no longer true. Against this position of the relativity of truth to individuals or cultures, there is the opposite view that truth is objective, not subjective and relative, that it is absolute and immutable, always and everywhere the same for all men.

Truth is what works

(1) Then there is the pragmatic attitude toward truth which says that truth consists in those ideas or those thoughts of ours which bear practical fruit in action that truth consists in the things which work. Truth is what works in the way of our thinking. And as against this emphasis on action and practical results as the measure of truth; there are those who say that such practical verification in action or experience is not needed at all for man’s having a grasp of the truth.

Truth is what corresponds from the mind with the reality

(1)The truth in the mind is the correspondence of the mind with reality, or the truth of our speech is a correspondence of what we say with what we think. If this is the case, then in the simple problem of telling the truth everyone except the pathological liar is able to know quite directly whether his own words faithfully express what he thinks. That correspondence between my speech and my thoughts is something that I myself can directly inspect. I have no problem of seeing whether or not my speech corresponds with my thought.

So I’d like to propose that here we follow the clear definition: a statement is true if it says that that which is is, or if it says that that which is not is not; and a statement is false if it says that that which is not is, or that that which is is not. I think anyone who has ever told a lie--and who hasn’t?--understands what this means: putting is where is not should be put or is not where is should be put.

But, there is the difficult problem of truth

(2) How do I test the correspondence between my own mind and reality, the world, to find out whether what I think is true? Let me show you why this is such a difficult case. Here we have the mind and here we have reality; and the mind is trying to know reality. In the mind is thought. Reality consists of existences. And those existences are things to be apprehended or known. But the thought, “Is that reality in my mind?” that thought is the reality that is apprehended. I don’t have in my mind two things, my thought and the object of my thought. Whatever is in my mind is in my mind, and I can’t know any “grasp of reality.” I have no way of getting hold of reality except by knowing it. But then I can’t test whether I know it or not by comparing what I know with what I am trying to know. Don’t you see that in this case you can’t make the comparison? There is no way of making a direct test between the two things that are supposed to correspond.

(3) Let me put it to you another way. I express my thoughts in statements or propositions. Reality consists of the facts about which I am trying to make the propositions. And the propositions are true if they correspond with the facts. And the facts are the things to be known. The facts not as known, but to be known. The propositions are the facts as I think I know them. It isn’t as if I had in one hand the propositions and in the other hand the facts and could look at them and say, “Oh, I see. My propositions correspond to the facts,” because I have no grasp of the facts except in my own propositions about them. Hence I have no way of making a direct comparison between my propositions and the facts they are trying to state. So there is no direct or even indirect way of telling whether what I think, what I say, my propositions and judgments, correspond with the way things are.

And there is not even an indirect way of doing this because I can’t ask “reality” questions the way I can ask another person questions and find out whether what I think agrees with what he thinks. I can’t ask reality questions. Or, I can ask the questions, but I can’t get any answers. Reality won’t speak back to me. And so there is no way of getting by communication the direct or indirect test of whether what I think, what is in my mind, corresponds with reality and the way things are. That is the problem of truth. It’s not the problem of knowing what truth is, but the problem of telling whether what I think is true is really true, if truth consists in the correspondence of my mind with reality

THE IMMUTABILITY OF TRUTH

(1) Is truth eternal or does it change? There’s no question that people change their minds that the human race in the course of centuries passes from knowledge to error or from error to knowledge in the opinions that it holds. But this is a change in the human mind and not a change in the truth or in what is true. For example, the opinion that the earth was flat, if it ever was false, is always false. And the opposite opinion, that the earth in which we live is round, if it ever was true, is always true. The fact that people have changed their minds about whether the earth is flat or round doesn’t make the truth of the matter itself change at all.

But you may say to me, Suppose that the earth tomorrow or next year were to change itself and suddenly become flat or oblong or something else, wouldn’t the proposition that the earth is round become false? No, because if I were careful and exact enough, I would say that from the beginning until this year, the earth has been round. So that if next year the earth changed its shape, my proposition still would be true, because it would always remain true that up to this year the earth had been round. Hence I think it is fair to say that truth itself is immutable, even if we as humans in our thinking do not possess the truth immutably.

OPINION VERSUS KNOWLEDGE

(1) Knowledge consists in having the truth and knowing that you have it, because you know why what you think is true is true. Whereas opinion consists in not being sure that you have the truth, not being sure whether what you say is true or false. And even if what you say happens to be true, you aren’t sure because you don’t know why it is true. This, I think, explains a difference all of us feel in the way of the words we use when we say, “I know that,” or a person says “I don’t know that; I only think that,” meaning I opine that, I don’t know it.

In the conduct of trials before judges in our courts there is a famous rule called the opinion rule. The opinion rule says that a witness giving testimony must report what he saw or what he heard. He must not report what he thinks happened, because that would be giving an opinion, not knowledge by observation.

Now the second point here, one which everybody knows, everyone is familiar with it, but perhaps you’ve never thought of it in these terms before, is the simple fact that opinions can be true or false. Opinions can be right or wrong. We all recognize this, I think. But think a moment, knowledge can’t be false, knowledge can’t be wrong. If something is knowledge, it’s impossible for it to be false knowledge or wrong knowledge.

(1) Truth is based on facts. It can be proven with evidence and tested with observation. It can be verified objectively and based on experience. And we cannot argue with it. One cannot argue that the sun will rise from the east. A statement is true if it agrees with the reality. Truth is based on reality or something that corresponds with reality. It can be found in the almanac, encyclopedias, text books dictionary, atlas, or Guinness Book of World Records. To identify the truth in an arguments, they must be based on statistics and questions like: Who (names), What (events), When (time), and Where (places).

Truth can be empirical truth and necessary truth. Empirical truth refers to the factual evidence of reality. It is a truth based on facts or experience. One example of this is “there are no Filipinos living in Antartica.” This is the correspondence theory of truth and the a posteriori type of truth since truth can be known after the experience while the necessary truth is coherence theory of truth. It is a truth based on reason. An example of this is “1+1 is equal to 2”. It is an a priori method of truth, that is, truth is known even before experience. A priori also means innate ideas- ideas that are “born into” us.

Two Schools of Thoughts based on epistemology:

RATIONALISM	EMPIRICISM
Necessary Truth	Empirical Truth
A-Priori	A-Posteriori
Knowledge is based on reason.	Knowledge is based on experience.
Existence of innate ideas	Tabula Rasa
Rene Descartes	John Locke
Baruch Spinoza	George Berkeley
Gottfried Wilhelm von Leibniz	David Hume
Immanuel Kant	John Stuart Mill
G. W. F. Hegel	Bertrand Russell

(2) Opinion is a kind of judgment. It is based on someone’s point of view. It is what someone thinks or feels. It may be supported with facts or personal emotions. It tells someone how one feels. It is a statement that holds an element of personal belief. It is not based on evidence. And it cannot be proven and tested. It is not founded on proof or certainty. It is not always true. But rather it may or may not be true. It can be used in an argument. One can agree or disagree with one’s opinion. These are statements which are still socially undecided.

(3) There are indicators to determine an opinion, like for example, I think, I believe. I feel, in my own opinion. Or we can determine it by using adjectives and adverbs, like “ugly” and “disgusting”, and “maybe, perhaps, best, always, probably, least, most, possibly or should.” Students must be able to determine whether what a person is saying is a fact or an opinion. Students must always remember that advertisements are opinions. Advertisement pretend to be based on facts, on reality, when really they are not. 99 percent of ads are opinions. Caution is always important when reading books or listening to a speaker. Magazines and newspapers carry opinions of writers and columnists, most especially the editorial page. Sometimes, if the column writer is trying to convince you of his point of view, it may seems like a truth, but it is still an opinion.

Questions to consider when reading books or listening to a speaker:

Which statements are truth and which statement is only an opinion:

Which statements can be proven, and correspond with reality?

Which statements are based only on the thoughts and mind of the writer or speaker?

EXAMPLES OF TRUTH AND OPINION:

TRUTH: Philippines is in Asia. (You cannot argue with this statement and it can be verified using reference books)

OPINION: Philippines is the best country in Asia. (You can agree or disagree)

TRUTH: Most classrooms have desks and chairs. (This statement can be proven through observation)

OPINION: I think classrooms should have couches. (The words “I think” indicates that this is only an OPINION)

TRUTH: Math is the study of numbers. (You cannot argue with this statement)

OPINION: Math is the hardest subject. (You can agree or disagree)

TRUTH: I am a Filipino.

OPINION: Filipinos are hospitable.