Underdetermination
Encyclopedia
In scientific theory, underdetermination refers to situations where the evidence available is insufficient to identify which belief we should hold about that evidence. For example, if all that was known was that 10 dollars was spent on apples and oranges, and that apples cost 1 dollar and oranges 2, then we would know that 9 apples were not purchased, but we could not know which combination of apples and oranges were purchased. In this example we would say that belief in what combination was purchased is underdetermined by the available evidence.
Underdetermination, again under different labels, arises in the modern period in the work of René Descartes
. Among other skeptical argument
s, Descartes presents two arguments demonstrating underdetermination.
Descartes's dream argument points out that, while dreaming, perceived experiences (for example, falling
) do not necessarily contain sufficient information to deduce the true situation (being in bed). Since one cannot always distinguish dreams from reality, one cannot rule out the theory that one is presently dreaming rather than having veridical
experiences; thus the theory that one is having a veridical experience is underdetermined.
Descartes's demon argument is a variant of the dream argument that posits that all of one's experiences and thoughts might be manipulated by a very powerful being (an "evil demon") that always deceives. Once again, so long as the perceived reality appears internally consistent to the limits of one's limited ability to tell, the situation is indistinguishable from reality, one cannot logically determine between correct belief from being misled; this is another version of underdetermination.
More serious cases of underdetermination are illustrated when a theory admits several possibilities for which the evidence says nothing. According to Isaac Newton's
mechanics, there is an absolute space in which events are located but all that can be detected are differences between velocities. Hence, it is equally consistent with this theory to say that the solar system is at rest, as it is to say that it moves at a velocity of 37 m/s in the direction from the center of the earth to the north pole. Newton himself indicated these two possibilities are indistinguishable.
Because arguments involving underdetermination involve both a claim about what the evidence is and that such evidence underdetermines a theory, it is often useful to separate these two claims within the underdetermination argument as follows:
The first premise makes the claim that a theory is underdetermined. The second says that rational decision (i.e. using available evidence) depends upon evidence that underdetermines the theory.
The poverty of the stimulus
argument and W.V.O. Quine (1960) 'Gavagai' example
are perhaps the most commented variants of the epistemological problem of the indeterminacy of data to theory.
. The skeptic argues that this undermines any claims to knowledge
, or even (by internalist definitions), justification
.
Philosophers have found this argument very powerful. Hume
felt it was unanswerable, but observed that it was in practice impossible to accept its conclusions. Influenced by this, Kant
held that while the nature of the 'noumenal' world was indeed unknowable, we could aspire to knowledge of the 'phenomenal
' world. A similar response has been advocated by modern anti-realists.
Underdetermined ideas are not implied to be incorrect (taking into account present evidences), rather we cannot know if they are correct. If we presuppose that conflict between different views means that none of them are correct, this is the Middle ground
fallacy.
, underdetermination is often presented as a problem for scientific realism
, which holds that we have reason to believe in unobservable entities (such as electrons) talked about by scientific theories. One such argument proceeds as follows:
Particular responses to this argument attack both the first and the second premise (1 and 2). It is argued against the first premise that the underdetermination must be strong and/or inductive. It is argued against the second premise that there is evidence for a theory's truth besides observations; for example, it is argued that simplicity, explanatory power or some other feature of a theory is evidence for it over its rivals.
A more general response from the scientific realist is to argue that underdetermination is no special problem for science, because, as indicated earlier in this article, all knowledge that is indirectly supported by evidence suffers from it - for example, conjectures concerning unobserved observables. It is therefore, ironically, too powerful an argument to have any significance in the philosophy of science, since it does not cast doubt uniquely on conjectured unobservables.
History of underdetermination
Ancient Greek skeptics argued for equipollence, the view that reasons for and against claims are equally balanced. This captures at least one sense of saying that the claims themselves are underdetermined.Underdetermination, again under different labels, arises in the modern period in the work of René Descartes
René Descartes
René Descartes ; was a French philosopher and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day...
. Among other skeptical argument
Argument
In philosophy and logic, an argument is an attempt to persuade someone of something, or give evidence or reasons for accepting a particular conclusion.Argument may also refer to:-Mathematics and computer science:...
s, Descartes presents two arguments demonstrating underdetermination.
Descartes's dream argument points out that, while dreaming, perceived experiences (for example, falling
Falling
Falling may refer to:*Falling , movement due to gravity*Falling *Falling *Falling *Falling , in which the goal is to hit the ground last...
) do not necessarily contain sufficient information to deduce the true situation (being in bed). Since one cannot always distinguish dreams from reality, one cannot rule out the theory that one is presently dreaming rather than having veridical
Veridical dream
The veridical dream is the dream which is afterwards fulfilled.* In Book XIX of the Odyssey, Penelopē said that "dreams ... which issue forth from the gate of polished horn bring true issues to pass, when any mortal sees them." * Likewise, Herodotos distinguished /oneiros/ as "the prophetic,...
experiences; thus the theory that one is having a veridical experience is underdetermined.
Descartes's demon argument is a variant of the dream argument that posits that all of one's experiences and thoughts might be manipulated by a very powerful being (an "evil demon") that always deceives. Once again, so long as the perceived reality appears internally consistent to the limits of one's limited ability to tell, the situation is indistinguishable from reality, one cannot logically determine between correct belief from being misled; this is another version of underdetermination.
Support for underdetermination
To show that a theory is underdetermined, one must show that there is a rival theory, equally well supported by the standards of evidence. A trivial example of underdetermination is the addition of an observer. For example, there is the theory that "objects near earth fall toward it when dropped". A rival theory is that "objects near earth fall when dropped but only if we check to see that they do". This rival is generated by taking any accepted theory and appending to it "whenever we look for evidence." Since one may append this to any theory, all theories are at least trivially underdetermined. If one considers such modifications of theories to be illegitimate then such "tricks" are not to be considered demonstrations of underdetermination.More serious cases of underdetermination are illustrated when a theory admits several possibilities for which the evidence says nothing. According to Isaac Newton's
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
mechanics, there is an absolute space in which events are located but all that can be detected are differences between velocities. Hence, it is equally consistent with this theory to say that the solar system is at rest, as it is to say that it moves at a velocity of 37 m/s in the direction from the center of the earth to the north pole. Newton himself indicated these two possibilities are indistinguishable.
Arguments involving underdetermination
Arguments involving underdetermination attempt to show that there is no reason for belief regarding some theory because it is underdetermined by the evidence. Since the evidence does not show that the theory is the uniquely true hypothesis, there is no reason to believe it rather than some equally supported rival.Because arguments involving underdetermination involve both a claim about what the evidence is and that such evidence underdetermines a theory, it is often useful to separate these two claims within the underdetermination argument as follows:
- All the evidence of a certain type underdetermines which of several rival theories is correct.
- Only evidence of that type is relevant to believing one of these theories.
- Therefore, there is no evidence for believing one among the rival theories.
The first premise makes the claim that a theory is underdetermined. The second says that rational decision (i.e. using available evidence) depends upon evidence that underdetermines the theory.
Epistemological problem of the indeterminacy of data to theory
Any phenomenon can be explained by a multiplicity of hypothesis. How, then, can data ever be sufficient to prove a theory? This is the epistemological problem of the indeterminacy of data to theory.The poverty of the stimulus
Poverty of the stimulus
In linguistics, the poverty of the stimulus is the assertion that natural language grammar is unlearnable given the relatively limited data available to children learning a language, and therefore that this knowledge is supplemented with some sort of innate linguistic capacity...
argument and W.V.O. Quine (1960) 'Gavagai' example
Indeterminacy of translation
The indeterminacy of translation is a thesis propounded by 20th century analytic philosopher W. V. Quine. The classic statement of this thesis can be found in his 1960 book Word and Object, which gathered together and refined much of Quine's previous work on subjects other than formal logic and set...
are perhaps the most commented variants of the epistemological problem of the indeterminacy of data to theory.
Underdetermination and general skeptical arguments
Some of the most powerful skeptical arguments appeal to the fact that all the evidence we could ever gather would still fail to determine which theory was true. It would remain compatible with 'skeptical hypotheses' like the maintenance of a complex illusion by Descartes' evil demon or (in a modern updating) the machines who run the MatrixThe Matrix
The Matrix is a 1999 science fiction-action film written and directed by Larry and Andy Wachowski, starring Keanu Reeves, Laurence Fishburne, Carrie-Anne Moss, Joe Pantoliano, and Hugo Weaving...
. The skeptic argues that this undermines any claims to knowledge
Knowledge
Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...
, or even (by internalist definitions), justification
Theory of justification
Theory of justification is a part of epistemology that attempts to understand the justification of propositions and beliefs. Epistemologists are concerned with various epistemic features of belief, which include the ideas of justification, warrant, rationality, and probability...
.
Philosophers have found this argument very powerful. Hume
David Hume
David Hume was a Scottish philosopher, historian, economist, and essayist, known especially for his philosophical empiricism and skepticism. He was one of the most important figures in the history of Western philosophy and the Scottish Enlightenment...
felt it was unanswerable, but observed that it was in practice impossible to accept its conclusions. Influenced by this, Kant
KANT
KANT is a computer algebra system for mathematicians interested in algebraic number theory, performing sophisticated computations in algebraic number fields, in global function fields, and in local fields. KASH is the associated command line interface...
held that while the nature of the 'noumenal' world was indeed unknowable, we could aspire to knowledge of the 'phenomenal
Phenomenon
A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...
' world. A similar response has been advocated by modern anti-realists.
Underdetermined ideas are not implied to be incorrect (taking into account present evidences), rather we cannot know if they are correct. If we presuppose that conflict between different views means that none of them are correct, this is the Middle ground
Middle ground
Argument to moderation is a logical fallacy which asserts that given two positions there exists a compromise between them which must be correct.An individual demonstrating the false compromise fallacy implies that the positions...
fallacy.
Underdetermination and philosophy of science
In the philosophy of sciencePhilosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...
, underdetermination is often presented as a problem for scientific realism
Scientific realism
Scientific realism is, at the most general level, the view that the world described by science is the real world, as it is, independent of what we might take it to be...
, which holds that we have reason to believe in unobservable entities (such as electrons) talked about by scientific theories. One such argument proceeds as follows:
- All the observational evidence for the unobservable entities of scientific theories underdetermines the claims of the theory about unobservable entities.
- Only the observational evidence is relevant to believing a scientific theory.
- Therefore, there is no evidence for believing what scientific theories say about unobservable entities.
Particular responses to this argument attack both the first and the second premise (1 and 2). It is argued against the first premise that the underdetermination must be strong and/or inductive. It is argued against the second premise that there is evidence for a theory's truth besides observations; for example, it is argued that simplicity, explanatory power or some other feature of a theory is evidence for it over its rivals.
A more general response from the scientific realist is to argue that underdetermination is no special problem for science, because, as indicated earlier in this article, all knowledge that is indirectly supported by evidence suffers from it - for example, conjectures concerning unobserved observables. It is therefore, ironically, too powerful an argument to have any significance in the philosophy of science, since it does not cast doubt uniquely on conjectured unobservables.
See also
- Poverty of the stimulusPoverty of the stimulusIn linguistics, the poverty of the stimulus is the assertion that natural language grammar is unlearnable given the relatively limited data available to children learning a language, and therefore that this knowledge is supplemented with some sort of innate linguistic capacity...
- Reference class problemReference class problemIn statistics, the reference class problem is the problem of deciding what class to use when calculating the probability applicable to a particular case...
- Scientific methodScientific methodScientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...
- InstrumentalismInstrumentalismIn the philosophy of science, instrumentalism is the view that a scientific theory is a useful instrument in understanding the world. A concept or theory should be evaluated by how effectively it explains and predicts phenomena, as opposed to how accurately it describes objective...
- Confirmation holismConfirmation holismConfirmation holism, also called epistemological holism is the claim that a single scientific theory cannot be tested in isolation; a test of one theory always depends on other theories and hypotheses....
- EquifinalityEquifinalityEquifinality is the principle that in open systems a given end state can be reached by many potential means. The term is due to Ludwig von Bertalanffy, the founder of General Systems Theory. He prefers this term, in contrast to "goal", in describing complex systems' similar or convergent behavior...
External links
- Underdetermination, explained at the Galilean Library
- Underdetermination and the Claims of Science by P.D. Magnus