We acquire knowledge about the existence of things through several
means. Direct observation is one of the most immediate ways in which
we encounter evidence of existence, but our knowledge is not limited
to what we personally observe. We also learn from the observations of
other people, from testimony, from reasoning, and from methods
designed to investigate things that cannot be directly observed.
Therefore, the central question of the Measurement of
Existence is not simply, “Did I observe this myself?”
but rather, “What grounds do I have for accepting that this
exists?” This distinction is important because much of what we
ordinarily consider knowledge comes from sources beyond our own
direct experience.
What Does the Mind Have Access To?
Our minds have direct access to observations obtained through our
senses: sight, hearing, touch, smell, and taste. These observations
provide information about the physical world as it appears to us.
However, observation alone does not automatically make every
conclusion drawn from an observation true. We can misunderstand what
we observe or misremember it. Therefore, observations themselves should
also be examined carefully.
Our minds also have access to internal states of consciousness, including our thoughts, emotions, feelings, memories, intentions, desires, sensations, mental images, imagination, and awareness of our own mental activity. Unlike information about the external world, which reaches the mind through sensory perception, these internal experiences are available through introspection and conscious awareness. The mind can therefore access both information about the world outside itself and experiences occurring within itself. However, access to an internal experience does not necessarily establish that the interpretation we give to that experience is correct. A memory can be inaccurate, an emotion can influence judgment, and a thought can be mistaken. These internal states can therefore provide information about our own consciousness while still requiring careful examination. Access to the external world, and the knowledge we acquire from observing it, is obtained through the senses.
Knowledge that comes from sources other than our own direct
observations requires a different form of evaluation. If another
person tells us that something exists, we are relying on testimony.
We may have good reasons to accept that testimony, such as the
reliability, expertise, or direct experience of the person providing
it. This does not mean that all testimony should be accepted or
rejected automatically. Rather, testimony should be evaluated
according to the evidence supporting it and the reliability of its
source. In this sense, the acceptance of knowledge obtained from
others involves an element of trust, but that trust can itself be
examined. The philosophical study of testimony similarly examines
when beliefs acquired from other people are justified and when they
amount to knowledge.
Claims concerning entities or phenomena that cannot be observed
through ordinary physical means require additional caution. In my
model, mysticism refers to claims of knowledge
concerning realities that are presented as accessible to the mind
despite lacking an observable basis. Such claims should not
automatically be accepted simply because they are experienced or
asserted with confidence. The important question is what evidence
exists for the claimed reality and whether the methods used to
establish it can be independently examined.
The Classifications of Knowledge
The following classifications describe how my Theory of
Acceptance of Knowledge evaluates different forms of
knowledge according to their relationship to evidence and the
existence of what they claim to describe.
Indisputable Knowledge
Knowledge that can be accepted with a
particularly high degree of confidence within the framework of the
Theory of Acceptance of Knowledge.
Observation-based Knowledge
Observation-based Knowledge
is knowledge obtained through direct observation. It concerns
information that is directly accessible to observation through the
senses or through instruments that extend our ability to observe.
Direct observation establishes that something was observed, although
conclusions about what the observation means or what will occur in
the future may require additional reasoning.
Scientific Knowledge
In this model, information is
considered scientific knowledge only when it has been obtained
through a systematic process of observation, hypothesis formation,
experimentation or testing, analysis, and evaluation according to the
scientific method. The defining characteristic of scientific
knowledge is therefore not simply that the information concerns
nature or is supported by evidence, but that the knowledge was
obtained through the scientific method.
When the scientific method produces a result that can
be independently tested and replicated under the appropriate
conditions, the result provides evidence that the phenomenon being
investigated exists and that the observed relationship is not merely
the result of an isolated observation. Replication is therefore an
important means of strengthening the acceptance of scientific
knowledge.
Under this classification, a claim does not become
scientific knowledge merely because it is stated by a scientist,
appears in a scientific publication, uses statistics, or concerns a
scientific subject. The method by which
the knowledge was obtained is what determines whether it qualifies as
scientific knowledge. This distinction
is important because scientific terminology or the appearance of
scientific research should not be confused with knowledge actually
obtained through the scientific method.
Knowledge of the Only Possibility
If we know that something is the only
possible explanation or outcome, then we
can accept it as knowledge. When multiple possibilities initially
exist, we can examine the available evidence and reasoning to
determine whether the alternatives can be eliminated. If all other
possibilities can be logically eliminated, the possibility that
remains is the only possibility,
and we can deduce it as the conclusion.
The process of eliminating alternative possibilities
can vary depending on the situation. A possibility may be eliminated
because it contradicts an observation, conflicts with an established
fact, or is logically impossible. The strength of the conclusion
therefore depends on whether all relevant alternatives have actually
been considered and whether the reasoning used to eliminate them is
sound.
When multiple possibilities remain and we cannot
eliminate all but one, we should not claim that we have knowledge of
the only possibility. Instead, we should acknowledge that multiple
possibilities exist and evaluate the evidence supporting each one. In
such cases, we may be able to determine that one possibility is more
likely than another, but likelihood
should be distinguished from knowing that something is the only
possibility.
Questionable Knowledge
Knowledge or claims that require further
consideration because their acceptance depends substantially on
evidence, testimony, estimation, interpretation, or methods whose
limitations must be examined.
Testimony-based Knowledge
Testimony-based Knowledge
is knowledge received through the testimony of another person or
source. We acquire an enormous amount of information through
testimony because we cannot personally observe everything that we
know about.
The acceptance of testimony should depend on factors
such as the authenticity of the evidence
supporting the testimony, the relevance and implications of that
evidence, and the reliability and competence of the source providing
the information. Testimony should
therefore neither be automatically accepted nor automatically
rejected. Its credibility should be evaluated according to the
evidence available to us.
Testimony-based knowledge can include historical
accounts, personal accounts, information provided by experts, and
observations reported by other people. The fact that information is
testimony-based does not make it false; rather, it means that the
recipient must evaluate the grounds for accepting information that
they did not personally observe.
Speculation-based Knowledge
Speculation-based Knowledge
is knowledge or a claim based substantially on speculation,
estimation, or incomplete information. Examples include estimates of
numerical values when an exact measurement is unavailable.
Speculation can be useful when it is clearly
identified as an estimate and is supported by a reasonable method and
relevant evidence. The problem arises when an estimate or speculation
is presented as though it were an established fact.
When evaluating speculation-based knowledge, two
important questions should be asked:
What method
was used to produce the estimation or speculation?
What evidence was used as the basis for
it?
The strength of a speculative conclusion should
correspond to the strength of the evidence supporting it.
Pseudo-scientific Knowledge
Pseudo-scientific Knowledge
consists of claims that present themselves as scientific knowledge
but are not adequately supported by scientific methods or standards
of evidence. The mere use of scientific terminology, numerical data,
experiments, or statistical information does not make a claim
scientific.
The methods used to obtain the evidence should
therefore be examined. If the methods do not adequately test the
claim, fail to control for important alternative explanations, rely
on unreliable measurements, or otherwise depart substantially from
accepted scientific practices, the resulting claim may warrant
classification as pseudo-scientific.
Statistical Knowledge
Statistical Knowledge
is knowledge derived from the collection and analysis of statistical
data. Statistical research can be scientifically rigorous and can
provide extremely strong evidence. However, statistical results can
be affected by problems such as fraud,
miscounts, biased sampling, measurement errors, uncontrolled
variables, inappropriate statistical methods, and selective analysis
of data. Researchers can also
unintentionally produce misleading conclusions through methodological
choices. For example, stopping data collection when a desired result
appears can increase the risk of obtaining a misleading result if the
procedure was not planned appropriately in advance.
Therefore, statistical knowledge should be evaluated
by examining how the data were collected,
how the sample was selected, what variables were measured, what
statistical methods were used, and whether the conclusions actually
follow from the data. Statistical
evidence should not automatically be considered unreliable, but
neither should a statistical result be accepted merely because it is
expressed numerically.
The Measurement of Existence
Observation-based Knowledge
A single observation, or even multiple observations, does not
necessarily establish that something will continue to exist or occur
in the future. We should distinguish between observing something and
establishing a reliable pattern of its occurrence.
For example, a cat that appears in the same location every day for
three weeks does not necessarily have to be there the next day. Our
previous observations provide evidence that the cat has been there
repeatedly, but they do not guarantee its future presence. The
distinction becomes particularly important when the factor being
observed is capable of changing its behavior or location.
Observation-based knowledge therefore establishes what has been
observed, while predictions about what will happen in the future
require additional reasoning. When a prediction depends on an
inconsistent factor, past observations alone may not be sufficient to
establish what the next observation will be.
There are also circumstances in which something that was directly
observable to one person becomes testimony-based knowledge for
someone else. If I personally observe an event and later tell another
person what I observed, that person does not possess my direct
observation. They possess my testimony about it. The epistemic status
of the information has therefore changed from direct observation for
the original observer to testimony for the recipient.
Knowledge of the Only Possibility
If we know that something is the only possibility, then we can
accept it as indisputable knowledge. In other cases where there are
multiple possible answers and all alternative possibilities can be
eliminated through sound reasoning, the possibility that remains can
be considered the only possibility. If the reasoning
used to eliminate the alternatives is correct, the conclusion does
not depend on estimating which possibility is merely more likely.
Instead, the alternatives have been shown to be incompatible with the
available information, leaving one remaining possibility.
The methods used to eliminate possibilities can vary according to
the situation. A possibility may be eliminated because it contradicts
an observation, violates a known fact, or produces a logical
impossibility. The important feature is that the elimination of
alternatives must itself have sufficient justification.
In situations involving testimony-based knowledge,
speculation-based knowledge, or claims presented as pseudo-scientific
knowledge, it may not be possible to eliminate every alternative. In
such cases, it is more appropriate to distinguish between what is
established and what is merely likely. We can describe possibilities
as highly unlikely, somewhat unlikely, or highly likely when the
available evidence supports such judgments, while recognizing that
likelihood is different from certainty.
If multiple possibilities remain, we should accept that multiple
possibilities remain. We should not force one possibility to become
“the truth” merely because we prefer it or because a decision
requires us to choose. Instead, we can evaluate the evidence
supporting each possibility and make the best-informed judgment
available. In this model, observation-based knowledge and knowledge
of the only possibility are therefore distinguished from claims whose
acceptance depends more heavily on testimony, speculation, or methods
that have not established the same degree of certainty.
Testimony-based Knowledge
Testimony-based knowledge consists of information that we accept
because it has been communicated to us by another person or source.
This includes historical accounts, personal accounts, scientific
information reported by researchers, information received from
experts, and many other forms of information that we did not
personally observe.
An educated evaluation of testimony should consider at least three
things: the authenticity of the evidence supporting the
information, the implications that the evidence has for the
information being communicated, and the reliability of the source
providing it. The credibility of the source matters because
people can be mistaken, misinformed, biased, or dishonest. At the
same time, testimony should not automatically be rejected simply
because it is not personally observed. Much of human knowledge
necessarily depends upon information received from others.
Epistemology recognizes testimony as an important source of knowledge
and asks precisely when reliance upon it is justified.
Testimony-based knowledge can include our knowledge of ancient and
modern history, the history of the Earth, observations made by other
people, personal accounts, and information communicated through
written or spoken language. The fact that such knowledge is
testimony-based does not necessarily make it false or unreliable.
Rather, it means that its acceptance requires an evaluation of the
testimony and the evidence behind it.
Speculation-based Knowledge
Speculation-based knowledge appears when we are asked to accept an
estimation or conclusion despite having incomplete information. There
are many circumstances in which estimation is necessary and useful,
but an estimation should be identified as an estimation rather than
presented as an established fact.
For example, suppose we are asked to determine the age of an
ancient archaeological artifact when no method exists for determining
its exact age. We may have enough evidence to produce an educated
estimate, but we should recognize the difference between the
estimated value and an exact measurement. The estimate may be highly
accurate, but its accuracy should not be confused with certainty.
Two important questions should therefore be asked when examining
speculation-based knowledge:
What method was used to
make the estimation?
What evidence was used as the basis for the
speculation?
These questions allow us to evaluate the quality of the reasoning
rather than merely accepting the conclusion. Recognizing speculation
as speculation is itself an important part of evaluating knowledge.
An estimate can be useful without being certain, and uncertainty does
not necessarily make an estimate worthless.
Pseudo-scientific Knowledge
Pseudo-scientific claims can lead us to believe that a trend or
phenomenon exists when the evidence or methods used to establish the
claim are inadequate. The most important factor in evaluating a
scientific-looking claim is therefore not simply the conclusion that
it produces, but the method used to produce it.
Statistical Knowledge
Statistical information can be useful for studying populations,
estimating trends, and evaluating risks. However, statistical results
are subject to limitations. Errors in measurement, biased sampling,
inaccurate data, fraud, miscounts, confounding factors, and
inappropriate statistical methods can all affect a conclusion. For
this reason, statistical evidence should be examined in relation to
how the data were collected and analyzed rather than accepted simply
because a numerical result has been produced.
A study based on a sample of a population does not necessarily
need to measure every member of that population to produce useful
information. Properly designed statistical methods are specifically
intended to draw conclusions about populations from samples while
accounting for uncertainty. The problem therefore is not that a
sample can never represent a population, but that conclusions can
become unreliable when the sample, methodology, analysis, or
interpretation is flawed.
For this reason, we should examine the methods used in a study and
consider the vulnerabilities to error that may have affected its
results. A study can provide useful evidence without establishing
absolute certainty. The question is therefore not simply, “Is this
study true?” but also, “What does the evidence actually
establish, how strong is that evidence, and does it justify the
conclusion being presented?”
Are Opinions Considered Truth?
An opinion should be distinguished from an objective fact. An
opinion is generally an interpretation, evaluation, or judgment
concerning something, rather than the existence of the thing itself.
For example, the fact that a particular sound exists can be
distinguished from a person's opinion about whether that sound is
pleasant. The sound exists independently of whether someone likes it,
while the person's evaluation of the sound depends upon their
perception and judgment.
This distinction demonstrates why truth cannot always be reduced
to whether someone believes something to be true. A person can
sincerely believe something and still be mistaken. The purpose of the
Measurement of Existence is therefore to examine the relationship
between what is believed, what exists, and the evidence available for
establishing that existence.
The central principle of this model can therefore be expressed as
follows:
“If
you measure truth by its existence, then you will know the truth.”
The purpose of the Measurement of Existence is not to claim that
every truth can be directly observed by an individual. Rather, it is
an attempt to establish a disciplined way of asking what grounds we
have for accepting something as true. When direct observation is
unavailable, we can examine testimony, evidence, reasoning,
methodology, and the remaining possibilities. When several
possibilities remain, we should acknowledge their existence as
possibilities rather than pretending that uncertainty has
disappeared.
In this way, the Theory of Acceptance of Knowledge
seeks to distinguish between what is directly established, what can
be established through reasoning, what is accepted through testimony,
and what remains speculative. The measurement of existence is
ultimately an effort to make our acceptance of knowledge correspond
as closely as possible to what the evidence allows us to conclude.
