Inverted spectrum
Encyclopedia
Inverted spectrum is the apparent possibility of two people sharing their color
vocabulary and discriminations, although the colours one sees — their qualia
— are systematically different from the colours the other person sees.
The argument dates back to John Locke
. It invites us to imagine that we wake up one morning, and find that for some unknown reason all the colors in the world have been inverted. Furthermore, we discover that no physical changes have occurred in our brains or bodies that would explain this phenomenon. Supporters of the existence of qualia argue that, since we can imagine this happening without contradiction, it follows that we are imagining a change in a property that determines the way things look to us, but that has no physical basis. In more detail:
The argument thus claims that if we find the inverted spectrum plausible, we must admit that qualia exist (and are non-physical). Some philosophers find it absurd that an "armchair argument" can prove something to exist, and the detailed argument does involve many assumptions about conceivability and possibility, which are open to criticism. Perhaps it is not possible for a given brain state to produce anything other than a given quale in our universe, and that is all that matters.
The idea that an inverted spectrum would be undetectable is also open to criticism on more scientific grounds:
Inverted spectrum arguments have applications to behavioralism
, physicalism
, representationalism, functionalism
, skepticism
and the hard problem of consciousness
.
In his book I Am A Strange Loop
, Douglas Hofstadter
argues that the inverted spectrum argument entails a form of solipsism
in which people can have no idea about what goes on in the minds of others—contrary to the central theme of his work. He presents several variants to demonstrate the absurdity of this idea: the "inverted political spectrum
", in which one person's concept of liberty
is identical to another's concept of imprisonment
; an inverted "sonic spectrum" in which low musical notes sound like "high" ones and vice versa (which he claims is impossible because low sounds can be felt physically as vibrations); and a version in which random, complex qualia
such as riding a roller coaster or opening presents are reversed, so that everyone perceives the world in radically different, unknowable ways.
Color
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
vocabulary and discriminations, although the colours one sees — their qualia
Qualia
Qualia , singular "quale" , from a Latin word meaning for "what sort" or "what kind," is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'. Examples of qualia are the pain of a headache, the taste of wine, the experience of taking a recreational drug, or the...
— are systematically different from the colours the other person sees.
John Locke
John Locke FRS , widely known as the Father of Liberalism, was an English philosopher and physician regarded as one of the most influential of Enlightenment thinkers. Considered one of the first of the British empiricists, following the tradition of Francis Bacon, he is equally important to social...
. It invites us to imagine that we wake up one morning, and find that for some unknown reason all the colors in the world have been inverted. Furthermore, we discover that no physical changes have occurred in our brains or bodies that would explain this phenomenon. Supporters of the existence of qualia argue that, since we can imagine this happening without contradiction, it follows that we are imagining a change in a property that determines the way things look to us, but that has no physical basis. In more detail:
- Metaphysical identityIdentity (philosophy)In philosophy, identity, from , is the relation each thing bears just to itself. According to Leibniz's law two things sharing every attribute are not only similar, but are the same thing. The concept of sameness has given rise to the general concept of identity, as in personal identity and...
holds of necessity - If something is possibly false, it is not necessaryModal logicModal logic is a type of formal logic that extends classical propositional and predicate logic to include operators expressing modality. Modals — words that express modalities — qualify a statement. For example, the statement "John is happy" might be qualified by saying that John is...
- It is conceivable that qualia could have a different relationship to physical brain-states
- If it is conceivable, then it is possibleLogical possibilityA logically possible proposition is one that can be asserted without implying a logical contradiction. This is to say that a proposition is logically possible if there is some coherent way for the world to be, under which the proposition would be true...
- Since it is possible for qualia to have a different relationship with physical brain-states, they cannot be identical to brain states (by 1).
- Therefore, qualia are non-physical.
The argument thus claims that if we find the inverted spectrum plausible, we must admit that qualia exist (and are non-physical). Some philosophers find it absurd that an "armchair argument" can prove something to exist, and the detailed argument does involve many assumptions about conceivability and possibility, which are open to criticism. Perhaps it is not possible for a given brain state to produce anything other than a given quale in our universe, and that is all that matters.
The idea that an inverted spectrum would be undetectable is also open to criticism on more scientific grounds:
Inverted spectrum arguments have applications to behavioralism
Behavioralism
Behavioralism is an approach in political science which seeks to provide an objective, quantified approach to explaining and predicting political behavior. It is associated with the rise of the behavioral sciences, modeled after the natural sciences...
, physicalism
Physicalism
Physicalism is a philosophical position holding that everything which exists is no more extensive than its physical properties; that is, that there are no kinds of things other than physical things...
, representationalism, functionalism
Functionalism (philosophy of mind)
Functionalism is a theory of the mind in contemporary philosophy, developed largely as an alternative to both the identity theory of mind and behaviourism. Its core idea is that mental states are constituted solely by their functional role — that is, they are causal relations to other mental...
, skepticism
Skepticism
Skepticism has many definitions, but generally refers to any questioning attitude towards knowledge, facts, or opinions/beliefs stated as facts, or doubt regarding claims that are taken for granted elsewhere...
and the hard problem of consciousness
Hard problem of consciousness
The hard problem of consciousness is the problem of explaining how and why we have qualitative phenomenal experiences. David Chalmers contrasts this with the "easy problems" of explaining the ability to discriminate, integrate information, report mental states, focus attention, etc...
.
In his book I Am A Strange Loop
I Am a Strange Loop
I Am a Strange Loop is a 2007 book by Douglas Hofstadter, examining in depth the concept of a strange loop originally developed in his 1979 book Gödel, Escher, Bach....
, Douglas Hofstadter
Douglas Hofstadter
Douglas Richard Hofstadter is an American academic whose research focuses on consciousness, analogy-making, artistic creation, literary translation, and discovery in mathematics and physics...
argues that the inverted spectrum argument entails a form of solipsism
Solipsism
Solipsism is the philosophical idea that only one's own mind is sure to exist. The term comes from Latin solus and ipse . Solipsism as an epistemological position holds that knowledge of anything outside one's own mind is unsure. The external world and other minds cannot be known, and might not...
in which people can have no idea about what goes on in the minds of others—contrary to the central theme of his work. He presents several variants to demonstrate the absurdity of this idea: the "inverted political spectrum
Political spectrum
A political spectrum is a way of modeling different political positions by placing them upon one or more geometric axes symbolizing independent political dimensions....
", in which one person's concept of liberty
Liberty
Liberty is a moral and political principle, or Right, that identifies the condition in which human beings are able to govern themselves, to behave according to their own free will, and take responsibility for their actions...
is identical to another's concept of imprisonment
Imprisonment
Imprisonment is a legal term.The book Termes de la Ley contains the following definition:This passage was approved by Atkin and Duke LJJ in Meering v Grahame White Aviation Co....
; an inverted "sonic spectrum" in which low musical notes sound like "high" ones and vice versa (which he claims is impossible because low sounds can be felt physically as vibrations); and a version in which random, complex qualia
Qualia
Qualia , singular "quale" , from a Latin word meaning for "what sort" or "what kind," is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'. Examples of qualia are the pain of a headache, the taste of wine, the experience of taking a recreational drug, or the...
such as riding a roller coaster or opening presents are reversed, so that everyone perceives the world in radically different, unknowable ways.
See also
- Dualism (philosophy of mind)Dualism (philosophy of mind)In philosophy of mind, dualism is a set of views about the relationship between mind and matter, which begins with the claim that mental phenomena are, in some respects, non-physical....
- FunctionalismFunctionalism (philosophy of mind)Functionalism is a theory of the mind in contemporary philosophy, developed largely as an alternative to both the identity theory of mind and behaviourism. Its core idea is that mental states are constituted solely by their functional role — that is, they are causal relations to other mental...
- The map is not the territoryMap–territory relationThe map–territory relation describes the relationship between an object and a representation of that object, as in the relation between a geographical territory and a map of it...
- Mary's RoomMary's roomMary's room is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" and extended in "What Mary Didn't Know"...
- Ontological argumentOntological argumentThe ontological argument for the existence of God is an a priori argument for the existence of God. The ontological argument was first proposed by the eleventh-century monk Anselm of Canterbury, who defined God as the greatest possible being we can conceive...
- Philosophy of mindPhilosophy of mindPhilosophy of mind is a branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain. The mind-body problem, i.e...
- Philosophy of perceptionPhilosophy of perceptionThe philosophy of perception is concerned with the nature of perceptual experience and the status of perceptual data, in particular how they relate to beliefs about, or knowledge of, the world. Any explicit account of perception requires a commitment to one of a variety of ontological or...
- PhysicalismPhysicalismPhysicalism is a philosophical position holding that everything which exists is no more extensive than its physical properties; that is, that there are no kinds of things other than physical things...
- QualiaQualiaQualia , singular "quale" , from a Latin word meaning for "what sort" or "what kind," is a term used in philosophy to refer to subjective conscious experiences as 'raw feels'. Examples of qualia are the pain of a headache, the taste of wine, the experience of taking a recreational drug, or the...
- Subjective character of experienceSubjective character of experienceThe subjective character of experience is a term in psychology and the philosophy of mind denoting that all subjective phenomena are associated with a single point of view...
- Philosophical zombies