Online research in philosophy

Functionalism, a philosophical theory, has empirical consequences. Functionalism predicts that where systematic transformations of sensory input occur and are followed by behavioral accommodation in which normal function of the organism is restored such that the causes and effects of the subject's psychological states return to those of the period prior to the transformation, there will be a return of qualia or subjective experiences to those present prior to the transform. A transformation of this type that has long been of philosophical interest is the possibility of an inverted spectrum. Hilary Putnam argues that the physical possibility of acquired spectrum inversion refutes functionalism. I argue, however, that in the absence of empirical results no a priori arguments against functionalism, such as Putnam's, can be cogent. I sketch an experimental situation which would produce acquired spectrum inversion. The mere existence of qualia inversion would constitute no refutation of functionalism; only its persistence after behavioral accommodation to the inversion would properly count against functionalism. The cumulative empirical evidence from experiments on image inversion suggests that the results of actual spectrum inversion would confirm rather than refute functionalism.

I argue that the inverted spectrum hypothesis is nota possibility we should take seriously. The principlereason is that if someone's qualia were inverted inthe specified manner there is reason to believe thephenomenal difference would manifest itself inbehaviour. This is so for two reasons. First, Isuggest that qualia, including phenomenal colours, arepartly constituted by an affective component whichwould be inverted along with the connected qualia. Theresulting affective inversions will, given theintimate connections that exist between emotions andbehaviour, likely manifest themselves in behaviour, inwhich case the underlying phenomenal differences canbe functionally captured. Second, I argue that othersense modalities lack the structural featuresnecessary for undetectable inversion which, because oftheir analogy with colour qualia, weakens theplausibility of such an inversion in the original caseof vision.

Abstract: The Inverted Earth case has seen fierce debate between Ned Block, who says it defeats the causal-covariational brand of wide representationalism about qualia, and Michael Tye and Bill Lycan, who say it does not. The debate has generated more heat than light because of a failure to get clear on who is supposed to be proving what, and what premises can be deployed in doing so. I argue that a correct understanding of the case makes it clear that the causal covariation theory is in deeper trouble over Inverted Earth than is generally supposed even by the theory's detractors.

There is reason to believe that people of different gender, race or age differ in spectra that are shifted relative to one another. Shifted spectra are not as dramatic as inverted spectra, but they can be used to make some of the same philosophical points.

Formerly a spectral apparition that haunted behaviorism and provided a puzzle about our knowledge of other minds, the inverted spectrum possibility has emerged as an important challenge to functionalist accounts of qualia. The inverted spectrum hypothesis raises the possibility that two individuals might think and behave in the same way yet have different qualia. The traditional supposition is of an individual who has a subjective color spectrum that is inverted with regard to that had by other individuals. When he looks at red objects, this individual has the qualia normally produced in others by blue objects. And when presented with a blue object, this individual experiences qualia that most persons experience only when presented with red objects. And so forth - the Invert's color spectrum is the inverse of normal; there are systematic inter-subjective differences in qualia.

(Wittgenstein, 1968) endorsed one kind of inverted spectrum hypothesis and rejected another. This paper argues that the kind of inverted spectrum hypothesis that Wittgenstein endorsed (the "innocuous" inverted spectrum hypothesis) is the thin end of the wedge that precludes a Wittgensteinian critique of the kind of inverted spectrum hypothesis he rejected (the "dangerous" kind). The danger of the dangerous kind is that it provides an argument for qualia, where qualia are (for the purposes of this paper) contents of experiential states which cannot be fully captured in natural language. I will pinpoint the difference between the innocuous and dangerous scenarios that matters for the argument for qualia, give arguments in favor of the coherence and possibility of the dangerous scenario, and try to show that some standard arguments against inverted spectra are ineffective against the version of the dangerous scenario I will be advocating. The leading idea of the paper is that an argument for qualia based on spectrum inversion does not require that the inversion be behaviorally indistinguishable. At one crucial point, I will rely on a less controversial version of an argument I gave in Block (1999). Wittgenstein's views provide a convenient starting point for a paper that is much more about qualia than about Wittgenstein.