Hard problem of consciousness

From Citizendium, the Citizens' Compendium
Jump to: navigation, search
This article is developing and not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.


The hard problem of consciousness is finding an explanation for how physical phenomena acquire subjective characteristics becoming, for example, colors and tastes.[1] For example, "it is possible to know all the physical and functional facts concerning the operation of human brains without, for example, knowing what it is like subjectively to experience vertigo."[2] As stated by Goldstein:[3]

Solving the "easy" problem of consciousness involves looking tor connections between physiological responses and experiences such as perceiving "red"... This is also called the search for the neural correlate of consciousness. Solving the "hard" problem of consciousness involves determining how physiological processes such as ions flowing across the nerve membrane cause us to have experiences.

—E. Bruce Goldstein, Sensation and Perception

The term hard problem of consciousness usually is attributed to David J. Chalmers.[4]

Some, perhaps most, scientists believe this problem ultimately will be explained by the developing methods of neuroscience:[5]

What we do not understand is the hard problem of consciousness — the mystery of how neural activity gives rise to subjective experience. Crick and [Christof] Koch have argued that once we solve the easy problem of consciousness, the unit of consciousness, we will be able to manipulate those neural systems experimentally to solve the hard problem.

—Eric R Kandel, In Search of Memory: The Emergence of a New Science of Mind

A kind of inverse to the hard problem that concerns the relation of physical causes to the subjective, is the problem of mental causation, the query as to how, or even if, mental events, like decisions, can cause physical events.[6] One facet of this topic is the placebo effect: does it indicate a real physical effect of the mind (perhaps via the brain) upon the body?[7]

“The study’s results shocked the investigators themselves: even patients who knew they were taking placebos described real improvement, reporting twice as much symptom relief as the no-treatment group.”

—Cara Feinberg, The placebo effect


  1. For a brief historical rundown, see James W. Kalat (2008). Biological Psychology, 10th ed. Cengage Learning, p. 7. ISBN 0495603007. 
  2. Barry Loewer. Edward Craig, general editor: Routledge Encyclopedia of Philosophy, Volume 6. Oxford University Press, p. 310. ISBN 0415073103.  referring to Nagel (What is it like to be a bat?, 1974) and to Jackson (What Mary didn't know, 1986)
  3. E. Bruce Goldstein (2010). “Something to consider: the mind-body problem”, Sensation and Perception, 8th ed. Cengage Learning, p. 39. ISBN 0495601497. 
  4. David J Chalmers (1995). "Facing up to the problem of consciousness". Journal of Consciousness Studies 2,: pp. 200-219. Reprinted in David J. Chalmers (1999). “Facing up to the problem of consciousness”, Jonathan Shear, ed: Explaining Consciousness: The Hard Problem. MIT Press, pp. 9 ff. ISBN 026269221X. 
  5. Eric R. Kandel (2007). “Part Five, §28: Consciousness”, In Search of Memory: The Emergence of a New Science of Mind. W. W. Norton & Company, p. 382. ISBN 0393329372. 
  6. (2008) Jens Harbecke: Mental Causation: Investigating the Mind's Powers in a Natural World. Ontos Verlag. ISBN 3938793945. 
  7. Cara Feinberg (January-February 2013). "The placebo phenomenon". Harvard Magazine.