Ned Block

Conceptual analysis, dualism, and the explanatory gap

The explanatory gap. Consciousness is a mystery. No one has ever given an account, even a highly speculative, hypothetical, and incomplete account of how a physical thing could have phenomenal states (Nagel 1974, Levine 1983). Suppose that consciousness is identical to a property of the brain-say, activity in the pyramidal cells of layer 5 of the cortex involving reverberatory circuits from cortical layer 6 to the thalamus and back to layers 4 and 6-as Crick and Koch have suggested for visual consciousness (Crick 1994). Still, that identity itself calls out for explanation! Proponents of an explanatory gap disagree about whether the gap is permanent. Some (e.g., Nagel 1974) say that we are like the scientifically naive person who is told that matter = energy, but does not have the concepts required to make sense of the idea. If we can acquire these concepts, the gap is closable. Others say the gap is unclosable because of our cognitive limitations (McGinn 1991). Still others say that the gap is a consequence of the fundamental nature of consciousness.

What psychological states are not

AS FAR as anyone knows, different organisms are often in psychological states of exactly the same type at one time or another, and a given organism is often in psychological states of exactly the same type at different times. Whenever either is the case, we shall say of the psychological states of the organism(s) in question that they are type identical. One thing that currently fashionable theories in the philosophy of mind often try to do is characterize the conditions for type identity of psychological states. For example, some varieties of philosophical behaviorism claim that two organisms are in typeidentical psychological states if and only if certain of their behaviors or behavioral dispositions are type identical. Analogously, some (though not all) varieties of physicalism claim that organisms are in type-identical psychological states if and only if certain of their physical states are type identical. In so far as they are construed as theories about the conditions for type identity of psychological states, it seems increasingly unlikely that either behaviorism or physicalism is true. Since

Psychologism and Behaviorism

I et psychologism be the doctrine that whether behavior is intelligent behavior depends on the character of the internal information processing that produces it. More specifically, I mean psychologism to involve the doctrine that two systems could have actual and potential behavior typical of familiar intelligent beings, that the two systems could be exactly alike in their actual and potential behavior, and in their behavioral dispositions and capacities and counterfactual behavioral properties (i.e., what behaviors, behavioral dispositions, and behavioral capacities they would have exhibited had their stimuli differed)-the two systems could be alike in all these ways, yet there could be a difference in the information processing that mediates their stimuli and responses that determines that one is not at all intelligent while the other is fully intelligent. This paper makes two claims: first, psychologism is true, and thus a natural behaviorist analysis of intelligence that is incompatible with psychologism is false. Second, the standard arguments against behaviorism are inadequate to defeat this natural behaviorist analysis of intelligence or to establish psychologism. While psychologism is of course anathema to behaviorists,1 it also seems wrong-headed to many philosophers who would not classify themselves as behaviorists. For example, Michael Dummett says:

Paradox and cross purposes in recent work on consciousness

Functionalists about consciousness identify consciousness with a role; physicalists identify consciousness with an implementer of that role. The global workspace theory of consciousness fits the functionalist perspective, but the physicalist sees consciousness as a biological phenomenon that implements global accessibility.

How heritability misleads about race

The Bell Curve revives and elaborates an argument given by Jensen to the effect that facts about heritability of IQ in whites dictate that blacks are genetically inferior in IQ. But clarification of the concept of heritability shows that this reasoning is fallacious. Heritability is an uninteresting measure that only misleads us about race.

How many concepts of consciousness

With some help from the commentators, a few adjustments to the characterizations of A-consciousness and P-consciousness can avoid some trivial cases of one without the other. But it still seems that the case for the existence of P without A is stronger than that for A without P. If indeed there can be P without A, but not A without P, this would be a remarkable result that would need explanation.

The Harder Problem of Consciousness

The aim of this paper is to present another problem of consciousness. The Harder Problem as I will call it is more epistemological than the Hard Problem. A second difference: the Hard Problem could arise for someone who has no conception of another person, whereas the Harder Problem is tied closely to the problem of other minds. Finally, the Harder Problem reveals an epistemic tension or at least discomfort in our ordinary conception of consciousness that is not suggested by the Hard Problem, and so in one respect it is harder. Perhaps the Harder Problem includes the Hard Problem and is best thought of as an epistemic add-on to it. Or perhaps they are in some other way facets of a single problem. Then my point is that this single problem breaks into two parts, one of which is more epistemic, involves other minds, and involves an epistemic discomfort.

Virtual Symposium on Virtual Mind

When certain formal symbol systems (e.g., computer programs) are implemented as dynamic physical symbol systems (e.g., when they are run on a computer) their activity can be interpreted at higher levels (e.g., binary code can be interpreted as LISP, LISP code can be interpreted as English, and English can be interpreted as a meaninguful conversation). These higher levels of interpretability are called ‘virtual’ systems. If such a virtual system is interpretable as if it had a mind, is such a ‘virtual mind’ real?This is the question addressed in this ‘virtual’ symposium, originally conducted electronically among four cognitive scientists. Donald Perlis, a computer scientist, argues that according to the computationalist thesis, virtual minds are real and hence Searles Chinese Room Argument fails, because if Searle memorized and executed a program that could pass the Turing Test in Chinese he would have a second, virtual, Chinese-understanding mind of which he was unaware (as in multiple personality). Stevan Harnad, a psychologist, argues that Searles Argument is valid, virtual minds are just hermeneutic overinterpretations, and symbols must be grounded in the real world of objects, not just the virtual world of interpretations. Computer scientist Patrick Hayes argues that Searles Argument fails, but because Searle does not really implement the program: a real implementation must not be homuncular but mindless and mechanical, like a computer. Only then can it give rise to a mind at the virtual level. Philosopher Ned Block suggests that there is no reason a mindful implementation would not be a real one.

Overflow, access, and attention

In this response to 32 commentators, I start by clarifying the overflow argument. I explain why the distinction between generic and specific phenomenology is important and why we are justified in acknowledging specific phenomenology in the overflow experiments. Other issues discussed are the relations among report, cognitive access, and attention; panpsychic disaster; the mesh between psychology and neuroscience; and whether consciousness exists.

The measurement problem in consciousness research

States of sensory absorption may offer a means to disentangle perception from report. Interestingly, such states lead to an antagonistic relationship between perceptual and cognitive-access networks, suggesting that perceptual awareness does not depend on a read-out by high order cognitive-access mechanisms. Rather, it may emerge internally, through a cooperative coding dynamics, whereby each neuron simultaneously represents and reads-out the perceptual awareness state.