by Jonathan Dolhenty, Ph.D.
We have a knowledge of
reality. Reality is presented to us by our senses
through the medium of percepts and our intellect
fashions concepts or ideas which are
representations of reality in an abstract and
universal manner. But mere percepts and concepts do
not as yet constitute knowledge; they are the raw
materials from which we make the finished
We have knowledge when
we affirm or deny something of something and that
takes place in an interpretive judgment made by us.
A judgment is always a mental pronouncement about
reality in some form or other, and this
pronouncement represents the actual condition of
reality as it is in itself. Judgments, therefore,
possess a truth-claim.
There are three truths which must be accepted at
the beginning of any investigation into the problem
of knowledge and truth:
- The First
Fact: The fact of our existence. "I
- The First
Principle: The principle of
contradiction. "A thing can not be and not-be at
the same time in the same respect."
- The First
Condition: The essential capability
of the mind to know truth. "My intellect can
reason and discover truth."
These primary truths cannot be "proved" by a
positive demonstration because they are presupposed
and involved in every demonstration. They are so
evident that any attempt to doubt or deny them
would already mean they have been affirmed and
accepted. They are, therefore, fully grounded in
reason and no reasonable person can dispute them
In fact, if anyone questions you as to their
truth, simply ask: "What will you accept as proof
for the truth of these three primary truths?" Put
the challenge to the opponent. No opponent can even
tell you what form of proof he would find
acceptable without accepting the truth of the three
primary truths in the first place!
Theories of Truth
falsehood may be applied to propositions,
but never to arguments. The attributes of
validity and invalidity can belong
only to deductive arguments, never to propositions.
It is very important to have a firm grasp of the
notions of true, false, valid, and invalid. Many
people get the "true" confused with the "valid" and
the "false" confused with the "invalid." Let's
first consider the terms "true" and
An idea itself cannot be, strictly speaking,
true or false. An idea is simply the intellectual
representation of a thing. An idea may be clear or
fuzzy, useful or useless, represent a real thing or
a non-existent thing, but it cannot, strictly
speaking, be true or false. An idea just "is." It
may be a good representation of a thing or a bad
representation of a thing.
The notion of true and false is applicable
only to judgments. Judgments are expressed in
propositions. Propositions express the agreement or
non-agreement between at least two ideas.
Therefore, only propositions may be properly said
to be true or false.
Arguments are made up of propositions.
Arguments are never "true" or "false." The
propositions making up the argument may be "true"
or "false," but not the argument itself. An
argument is either "valid" or "invalid." More about
this in a moment.
The meaning of truth and falsity is very
important. What is truth? How do we know that a
proposition is true? As far as we know at the
present time, there seems to be only three tests of
This is probably the most common way in which we
check to see whether or not a judgment is true. All
we have to do is check our judgment with what
really is the case and if our judgment corresponds
to what is the case, we say the judgment is true.
Basically, truth rests on the conformity or
correspondence of our mind with reality.
Let's suppose one of us says, "It is raining
outside." This is a judgment expressed in a
sentence called a proposition. How do we know if
it's true? Well, we can go outside and check to see
if our judgment is correct, that is, if it is true.
If it is raining outside, the judgment is true. Our
judgment has conformed to or is in correspondence
with the fact that it is raining outside.
We can check many fact-claims this way. Go look!
Go feel! Go hear! Go taste! Go smell! In order to
apply the correspondence test, we have to have two
- The judgment we make about something,
- Real objects or events to which the judgment
If it corresponds, the judgment is true; if not,
the judgment is false. Keep in mind, however, it is
possible to have a judgment we cannot be certain is
true or false. We may express a judgment as an
opinion, informed or otherwise, because we are not
certain whether or not it is true or false.
According to this test, a judgment may be
accepted as true if it harmonizes or is coherent
with other facts which we have already accepted as
true. This test becomes very valuable when we don't
have access to a personal observation for
ourselves. This test is useful in the discipline of
history, for instance, where we don't have direct
observation of past events. We also use it when we
cannot personally witness an event.
Let's suppose someone says to us, "There are
sharks in the Mississippi River." We would reject
this judgment and say it is untrue. Why? We already
know that sharks cannot live in fresh water. We
already know that the Mississippi River consists of
fresh water. We can't make the judgment, "There are
sharks in the Mississippi River," fit coherently
with what we already know about sharks and the
This is a fairly recent test of truth and is
applicable to only certain judgments made in
specific situations. This theory says that the
truth of a judgment can be determined by its
results. Basically, it says that "if a judgment
works, it's true."
The problem with this theory of truth is that it
is extremely limited and can lead to abuses when
applied inappropriately. For instance, there are
many cases where something "works," but we would
not say it's true. This test of truth does not work
well with statements of "fact," and one could argue
that it really doesn't test "facts" at all. What it
can test is a hypothesis or a judgment made on the
basis of trial and error.
If we examine carefully the three theories of
truth presented above, we can reasonably draw the
following conclusions. The Coherence Theory and the
Pragmatic Theory are not primarily tests of truth
at all. They are, at best, only secondary tests of
The Coherence Theory demands that an initial
judgment or several initial judgments be "true" in
the first place. These initial judgments can be
determined to be true only by applying the
Correspondence Theory of truth. Without the truth
of the primary truths determined by the
correspondence test, the coherence test is subject
The Pragmatic Theory is also a secondary test.
It demands that "facts" be true at the outset, in
setting up a hypothesis for instance, and also
requires that our judgment regarding the results
involving the hypothesis be true in the sense of
corresponding to what is actually the case. Without
the Correspondence Theory of truth, the Pragmatic
Theory is useless.
We may use the coherent test or the pragmatic
test at some point in an argument, an
investigation, or an experiment, but we need the
correspondence test at the beginning and we need it
at the end. That is why we can define truth as "the
correspondence of our judgment with reality" or
"the correspondence of a proposition with what is
actually the case." The Correspondence Theory is,
therefore, the primary test of truth. The Coherence
Theory and the Pragmatic Theory are only secondary
tests and are initially dependent on the
We have learned that truth
and falseness are attributes of a judgment. Only a
judgment can be said to be true or false and
judgments are expressed in propositions that can,
therefore, be said to be true or false.
Furthermore, we have learned that arguments, and
not propositions, are valid or invalid.
Additionally, we have learned that these terms
apply only to deductive arguments. What do we mean
by valid and invalid?
A deductive argument is valid when its
premises, if true, provide conclusive grounds for
its conclusion. This means that the premises
and conclusion are so related that it is absolutely
impossible for the premises to be true unless the
conclusion is true also. Every deductive argument
is either valid or invalid.
It is possible for the conclusion of a deductive
argument to be true but invalid. It is also
possible for the conclusion of a deductive argument
to be false but perfectly valid. We can see that
"truth" and "validity" do not have an essential
relationship with one another.
"Truth" means a conforming of judgment (or
proposition) with reality. "Validity" mean a
consistent and proper relationship between
propositions and conclusions according to certain
rules of logical thinking.
Again, it is very important to keep in mind that
only propositions are true or false, and only
deductive arguments are valid or invalid.
Before we leave this matter of valid and invalid
arguments, we need to consider that other branch or
type of logic called the inductive argument. Are
inductive arguments valid or invalid? Strictly
speaking, they are neither valid nor invalid.
Inductive arguments are evaluated as better or
worse, according to the strength of the support
provided their conclusions by their premises.
Here we enter the world of probability, an exciting
world that actually impacts our lives everyday.
The term "evidence" is
used often in everyday discourse and,
unfortunately, it is also used loosely, so let's
take a brief look at the types of evidence we may
Some truths (very few, of course) are what we
call "self-evident." This is sometimes called
"immediate" evidence because it requires no
thinking out, no medium of reasoning through which
it can be made to appear. It appears at once and
directly. We know it immediately without having to
work it out. The three primary truths mentioned
above are examples of truths based on immediate
evidence. Another example is the truth, "A totality
is greater than any one of its parts." If we
understand what is meant by "totality" and "part,"
we can immediately see the truth of the
Another type of evidence is "mediate"
evidence. Most of the time, truth does not
appear to us immediately and must be sought by some
other method. It must be worked out through the
medium of reasoning. We do not know immediately
that water boils at 212 degrees F. at sea level. It
has to be worked out. Of course, once scientists
worked it out, we can accept it based on their
authority. But if we doubted the truth of it, we
could actually do the necessary experiments
ourselves to establish the evidence for the truth
of the matter.
Evidence, to be of any value to us, must be
objective. It must not be a mere feeling or
simply an opinion or a matter or personal taste. In
other words, evidence must not be subjective.
The ultimate criterion of truth, as we shall see
shortly, is, then, objective evidence, and is
based on three possible sources:
- The evidence of the senses which, rightly
used, are infallible.
- The evidence of the intellect which, using
its ideas to form judgments based on correct
reasoning methods, can formulate true
propositions which are in accord with
- The evidence of authority which is reliable
testimony. There are strict rules for evidence
from authority and there are tests which can be
applied to evaluate the reliability of any
authoritative source. Much, if not most, of our
knowledge comes from the evidence of authority.
We accept the findings of trained historians,
for example, as well as the findings of
However, we must be cautious even accepting the
authority of historians and scientists and, for
that matter, any person claiming to be an
authoritative source. All authority must be willing
to be challenged, although normally we would not go
around challenging every one all the time. It is
the willingness to be challenged that is important.
Historians have been wrong in the past about
historical data. They have even lied on occasion.
Scientists have been wrong about scientific
matters. They have also been known to "cook the
books." And judges, lawyers, juries, priests,
ministers, physicians, and so forth, have been in
error on many occasions.
It is an unfortunate fact
that our judgments are not always true, and we need
to establish the criterion to be used to determine
truth and error. What constitutes truth and error?
How can we discriminate between true and erroneous
judgments? What is the proper test of
We have said that an idea is the intellectual
representation of a thing. We are, however,
incapable of grasping the full reality of an object
within the content of a single idea due to the
limited power and capacity of our intellect.
Because of this limitation, our intellect turns its
attention first to this, then to that property or
attribute of a thing, and makes a separate concept
for each one.
Things in nature are actually undivided and one,
although potentially divisible and many. But in our
intellect, the ideas of things are actually divided
and many, although potentially undivided and one.
None of our ideas represents the full reality of
things, but each idea represents an aspect, a
phase, or a portion of the thing.
The material object of the idea is the total
object in all its properties and attributes. The
formal object of the idea is the thing in its
single property or attribute in so far, of course,
as it is represented by the single idea.
In order that the idea be a correct
representation of the thing, it must agree with its
formal object. The idea, then, is seen to be a
piecemeal representation, but it is correct as far
as it goes. To be incomplete is not the same as to
Our intellect acquires a more or less complete
grasp of a thing by means of a mental division of
its reality into a number of concepts. It
subsequently makes a mental synthesis of the
objects and its attributes in the judgment.
What was divided in the process of abstraction
becomes united in the act of making a judgment.
Consider these judgments:
- That dog is black.
- That dog has four legs.
- That dog can run fast.
In each case, the attribute, presented as the
predicate, is referred back to the thing, presented
as the subject. The subject "dog" stands for the
thing in a general way, while the predicates,
"black," "four legs," and "run fast," stand for the
particular attributes which belong to the thing.
These attributes are recognized as belonging to the
thing in its objective existence.
What the judgment pronounces of its ideas is
meant to be pronounced of the reality itself
because ideas are partial, yet correct,
representations of objective reality.
Every judgment implicitly expresses a
correspondence between the thing as it is in
itself, and as it exists ideally in the intellect.
Explicitly, the judgment merely pronounces an
identity between the predicate-idea and the
subject-idea. Such is the nature of an affirmative
Regarding a negative judgment, much the same can
be said. Here we take an attribute not found in the
thing and deny its presence in the thing. The
predicate-idea is excluded from the subject-idea.
We assert that the reality designated by the
predicate is lacking in the thing designated by the
subject. Here again we express a conformity between
the reality as it exists in nature and as it exists
ideally in our intellect. When we say, "That dog is
not black," we pronounce the non-identity between
subject and predicate or thing and
Truth and error, then, reside in the judgment,
not in the ideas taken alone by themselves. Truth
can now be defined as the conformity of judgment to
reality. Error can now be defined as the
disconformity of judgment to reality. This is in
accord with our common sense, everyday meaning of
Knowledge is useless if
it does not agree with reality.
A criterion of truth is a rule, or norm, or
standard, or test by which we distinguish true
judgments from those which are false. Since the
judgment is a natural mental process, the criterion
of truth must be a natural norm or test, well
within the reach of every individual. Since the
judgment is an intellectual process, the criterion
of truth must be discoverable by the intellect.
Certitude is that state of the mind in which
the mind gives a firm assent to a judgment without
fear of error, due to recognized valid reasons.
The valid reasons, according to their convincing
- Moral certitude: based on the customary
action of human beings, and exceptions to the
law are recognized as physically possible, i.e.,
"We are sure that parents love their
- Physical certitude: rests on the physical
laws of the world, and exceptions here are
impossible in the ordinary course of nature,
i.e., "Iron will sink in water";
- Metaphysical certitude: has its foundation
in the metaphysical laws of being, so that an
exception is intrinsically impossible, it would
involve an internal contradiction, i.e., "The
whole is greater than any of its parts."
Whenever we are certain in such judgments, we
are conscious of a motive of certitude.
We can distinguish between subjective and
objective certitude. Subjective certitude consists
in the mere firmness of our assent, and it does not
exclude error in our judgment. It does exclude the
fear of error, considered solely as a subjective
state of the mind itself.
Objective certitude consists in the reasons
contained in the terms of the judgment, in virtue
of which the judgment is considered to be a true
representation of reality.
The same reasons which determine the truth of
the judgment determine also the certitude of the
assent. Hence, the criterion of truth and the
motive of certitude are objectively identical,
although conceptually different.
The criterion of truth is objective
Objective evidence is that
characteristic of reality whereby it becomes
objectively manifest to the perceiving faculty.
There are various kinds of objective
Internal evidence: exists when the ground
for our judgment is clearly perceived to lie in the
reality affirmed by the judgment. It is immediate
if this interpreted reality is directly presented
to the intellect or the senses. For example,
"2+2=4," and "This paper is white." It is mediate
if this interpreted reality is not directly
presented to the intellect or the senses, but is
presented in some other way. For example, a process
of reasoning, or ballistic evidence used, for
instance, by the police.
External evidence: exists when the ground
for our judgment lies, not in the reality itself
affirmed by the judgment, but in some other reality
outside it. For example, from some authority and it
rests on the evidence of the motives of
credibility, such as a witness to some event or
some historical evidence. Or by imprudence of
doubt, when it is not sufficient to compel our
assent, but is clearly perceived to be sufficient
to exclude all unreasonable doubt. For example, a
complex mathematical problem performed by a
mathematician whose credibility is unquestionable.
Or one who claims to be my mother, even if I can't
provide evidence at the moment.
Evidence is the Criterion of Truth.
It is important to realize that a strict
demonstration of the fact that evidence is the
criterion of truth is impossible. Primary facts
cannot be demonstrated, but are shown to be true by
an appeal to fundamental experience and reflection.
For example, I cannot demonstrate that I can see,
the fact of seeing is its own proof. Similarly, I
cannot demonstrate that evidence is the criterion
of truth because it would require the criterion of
truth to prove that it is true, and this is the
fallacy of "begging the question."
Experience and reflection clearly show that
as a matter of fact objective evidence is the
criterion of truth and our motive of
We do not arbitrarily apply predicates to
subjects and consider such judgments true.
The intellect needs a ground or reason outside
itself because judgments are clearly perceived to
be interpretations of reality outside our
The clear presentation of reality is the ground
for considering judgments to be true and worthy of
firm assent, and that is the objective evidence of
The difference between the attitudes of the
intellect in certitude, doubt, and opinion is due
to the difference of reality in its self-revelation
to the mind.
This analysis of truth and certitude shows that
objective evidence of reality, or reality itself as
clearly manifested to the intellect, is the
criterion of truth and the motive of our certitude.
Without it, our intellect must remain in doubt or,
at the very best, can form only a probable opinion,
and then the fear of error will always be
The ultimate criterion and ultimate motive must
be such as to exclude the possibility of doubt or
error. To do this, reality must be self-evident.
The external evidence of authority and of the
imprudence of doubt does not exclude the
possibility of doubt and error, and mediate
evidence always rests on immediate evidence.
Experience proves that all knowledge derives its
validity from a few fundamental principles which
are self-evident, because they are based on the
self-evident concepts of being and non-being.
The Causes of
Error is not caused by
reality because reality reveals itself as it is.
Nor is it caused by the mind directly because it
tends toward truth.
Error is the result of the influence of the will
on the intellect, inducing the intellect to assent
to a judgment without sufficient objective evidence
on the part of reality.
The factors which move the will in this way
- The complexity of reality;
- Imperfections in the sense organs;
- The necessity of action;
- Partisanship and prejudice;
- Emotional instability.
- The desire to shirk protracted labor.
Error, therefore, is not an inherent
characteristic either of reality or of the
intellect. It is the result of the determining
influence of the will.
Error as such is incidental and accidental to
judgments. We must pay proper attention to the
objective evidence of reality. In this way, we can
avoid error. Then our judgments are essentially
valid as true interpretations of reality.
Your Life With a Philosophy