Moore's paradox concerns the apparent absurdity involved in asserting a first-person present-tense sentence such as "It is raining, but I do not believe that it is raining" or "It is raining, but I believe that it is not raining." The first author to note this apparent absurdity was
George E. Moore.
These 'Moorean' sentences, as they have become known, are paradoxical in that while they appear absurd, they nevertheless
# Can be true;
# Are (logically) consistent; and
# Are not (obviously)
contradictions.
The term 'Moore's paradox' is attributed to
Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
From 1929 to 1947, Witt ...
, who considered the paradox Moore's most important contribution to philosophy. Wittgenstein wrote about the paradox extensively in his later writings, which brought Moore's paradox the attention it would not have otherwise received.
Moore's paradox has been associated with many other well-known
logical paradoxes, including, though not limited to, the
liar paradox, the
knower paradox, the
unexpected hanging paradox, and the
preface paradox.
There is currently not any generally accepted explanation of Moore's paradox in the philosophical literature. However, while Moore's paradox remains a philosophical curiosity, Moorean-type sentences are used by
logicians,
computer scientist
A computer scientist is a scientist who specializes in the academic study of computer science.
Computer scientists typically work on the theoretical side of computation. Although computer scientists can also focus their work and research on ...
s, and those working with
artificial intelligence
Artificial intelligence (AI) is the capability of computer, computational systems to perform tasks typically associated with human intelligence, such as learning, reasoning, problem-solving, perception, and decision-making. It is a field of re ...
as examples of cases in which a knowledge, belief, or information system is not modified in response to new data.
The problem
Since
Jaakko Hintikka's seminal treatment of the problem,
it has become standard to present Moore's paradox by explaining why it is absurd to assert sentences that have the logical form:
"P and NOT(I believe that P)" or "P and I believe that NOT-P."
Philosophers refer to these, respectively, as the omissive and commissive versions of Moore's paradox.
Moore himself presented the problem in two versions.
The more fundamental manner of stating the problem starts from the three premises following:
# It can be true at a particular time both that P, and that I do not believe that P.
# I can assert or believe one of the two at a particular time.
# It is absurd to assert or believe both of them at the same time.
I can assert that it is raining at a particular time. I can assert that I don't believe that it is raining at a particular time. If I say both at the same time, I am saying or doing something absurd. But the content of what I say—the
proposition
A proposition is a statement that can be either true or false. It is a central concept in the philosophy of language, semantics, logic, and related fields. Propositions are the object s denoted by declarative sentences; for example, "The sky ...
the sentence expresses—is perfectly consistent: it may well be raining, and I may not believe it. So why can I not assert that it is so?
Moore presents the problem in a second, distinct, way:
# It is not absurd to assert the past-tense counterpart; e.g., "It was raining, but I did not believe that it was raining."
# It is not absurd to assert the second- or third-person counterparts to Moore's sentences; e.g., "It is raining, but ''you'' do not believe that it is raining," or "Michael is dead, but ''they'' do not believe that he is."
# It is absurd to assert the present-tense "It is raining, and I don't believe that it is raining."
I can assert that I ''was'' a certain way—e.g., believing it was raining when it wasn't—and that you, he, or they ''are'' that way but not that I ''am'' that way.
Subsequent philosophers have said that there is an apparent absurdity in asserting a first-person ''future-tense'' sentence such as "It will be raining, and I will believe that it is not raining."
Proposed explanations
Philosophical interest in Moore's paradox, since Moore and Wittgenstein, has experienced a resurgence, starting with, though not limited to,
Jaakko Hintikka,
continuing with Roy Sorensen,
David Rosenthal,
Sydney Shoemaker and the first publication, in 2007, of a collection of articles devoted to the problem.
There have been several proposed constraints on a satisfactory explanation in the literature, including (though not limited to):
*It should explain the absurdity of both the omissive and the commissive versions.
*It should explain the absurdity of both asserting and believing Moore's sentences.
*It should preserve, and reveal the roots of, the intuition that contradiction (or something contradiction-like) is at the root of the absurdity.
The first two conditions have generally been the most challenged, while the third appears to be the ''least'' controversial. Some philosophers have claimed that there is, in fact, no problem in believing the content of Moore's sentences (e.g. David Rosenthal). Others (e.g. Sydney Shoemaker) claim that an explanation of the problem at the level of belief will automatically provide us with an explanation of the absurdity at the level of assertion via the linking principle that what can reasonably be asserted is determined by what can reasonably be believed. Some have also denied (e.g. Rosenthal) that a satisfactory explanation to the problem need be uniform in explaining both the omissive and commissive versions. Most of the explanations offered of Moore's paradox are united in claiming that
contradiction is the basis of the absurdity.
One type of explanation at the level of assertion is that assertion implies or expresses
belief
A belief is a subjective Attitude (psychology), attitude that something is truth, true or a State of affairs (philosophy), state of affairs is the case. A subjective attitude is a mental state of having some Life stance, stance, take, or opinion ...
in some way, so that if someone asserts that ''p'' they imply or express the belief that ''p''. Several versions of this opinion exploit elements of
speech act
In the philosophy of language and linguistics, a speech act is something expressed by an individual that not only presents information but performs an action as well. For example, the phrase "I would like the mashed potatoes; could you please pas ...
theory, which can be distinguished according to the particular explanation given of the link between assertion and belief. Whatever version of this opinion is preferred, whether cast in terms of the Gricean intentions (see
Paul Grice
Herbert Paul Grice (13 March 1913 – 28 August 1988), usually publishing under the name H. P. Grice, H. Paul Grice, or Paul Grice, was a British philosopher of language who created the theory of implicature and the cooperative principle ( ...
) or in terms of the structure of Searlean illocutionary acts
An alternative position is that the assertion "I believe that ''p''" often (though not always) functions as an alternative way of asserting "''p''", so that the semantic content of the assertion "I believe that ''p''" is just ''p'': it functions as a statement about the world and not about anyone's state of mind. Accordingly, what someone asserts when they assert "''p'' and I believe that not-''p''" is just "''p'' and not-''p''" Asserting the commissive version of Moore's sentences is again assimilated to the more familiar (putative) impropriety of asserting a
contradiction.
Another alternative opinion, due to
Richard Moran,
considering the existence of Moore's paradox as symptomatic of creatures who are capable of self-knowledge, capable of thinking ''for'' themselves from a deliberative point of view, as well as ''about'' themselves from a theoretical point of view. On this view, anyone who asserted or believed one of Moore's sentences would be subject to a loss of self-knowledge—in particular, would be one who, with respect to a particular 'object', broadly construed, e.g. person, apple, the way of the world, would be in a situation which violates, what Moran calls, the Transparency Condition: if I want to know what I think about X, then I consider/think about nothing but X itself. Moran's opinion seems to be that what makes Moore's paradox so distinctive is not some contradictory-like phenomenon (or at least not in the sense that most commentators on the problem have construed it), whether it be located at the level of belief or that of assertion. Rather, that the very possibility of Moore's paradox is a consequence of our status as agents (albeit finite and resource-limited ones) who are capable of knowing (and changing) their own minds.
See also
*
Belief
A belief is a subjective Attitude (psychology), attitude that something is truth, true or a State of affairs (philosophy), state of affairs is the case. A subjective attitude is a mental state of having some Life stance, stance, take, or opinion ...
*
Consistency
In deductive logic, a consistent theory is one that does not lead to a logical contradiction. A theory T is consistent if there is no formula \varphi such that both \varphi and its negation \lnot\varphi are elements of the set of consequences ...
*
Doublethink
*
Doubt
Doubt is a mental state in which the mind remains suspended between two or more contradictory propositions, and is certainty, uncertain about them.
Doubt on an emotional level is indecision between belief and wikt:disbelief, disbelief. It may i ...
*
Doxastic logic
*
Epistemology
Epistemology is the branch of philosophy that examines the nature, origin, and limits of knowledge. Also called "the theory of knowledge", it explores different types of knowledge, such as propositional knowledge about facts, practical knowle ...
*
Contradiction
*
Irrationality
Irrationality is cognition, thinking, talking, or acting without rationality.
Irrationality often has a negative connotation, as thinking and actions that are less useful or more illogical than other more rational alternatives. The concept o ...
*
List of paradoxes
*
Philosophy of mind
Philosophy of mind is a branch of philosophy that deals with the nature of the mind and its relation to the Body (biology), body and the Reality, external world.
The mind–body problem is a paradigmatic issue in philosophy of mind, although a ...
*
Rationality
Rationality is the quality of being guided by or based on reason. In this regard, a person acts rationally if they have a good reason for what they do, or a belief is rational if it is based on strong evidence. This quality can apply to an ab ...
*
Self-knowledge (psychology)
Self-knowledge is a term used in psychology to describe the information that an individual draws upon when finding answers to the questions "What am I like?" and "Who am I?".
While seeking to develop the answer to this question, self-knowledge r ...
*
Self-deception
Notes
References
External links
"Epistemic Paradoxes" (including Moore's) at the ''Stanford Encyclopedia of Philosophy''
{{DEFAULTSORT:Moore's Paradox
Epistemic paradoxes
Pragmatics