Online research in philosophy

Hallucinations occur in a wide range of organic and psychological disorders, as well as in a small percentage of the normal population According to usual definitions in psychology and psychiatry, hallucinations are sensory experiences which present things that are not there, but are nonetheless accompanied by a powerful sense of reality. As Richard Bentall puts it, “the illusion of reality ... is the sine qua non of all hallucinatory experiences” (Bentall 1990: 82). The aim of this paper is to find out what lends an experience ‘a sense of reality’: what features are required for an experience to feel ‘real’, in the relevant sense? I will investigate the claim that phenomenological features are largely responsible for a sense of reality, and will find this claim wanting. My suggestion is that a sense of reality is created and sustained by the larger nexus of the subject's beliefs.

Pike’s phenomenology of mystical experiences articulates sharply where theological content may enter the structure of Christian mystics’ experiences (as characterized in their own words). Here we look to Buddhist (and other) accounts of pure or nibbanic consciousness attained in experiences of deep meditation. A contemporary modal model of inner awareness is considered whereby a form of pure consciousness underlies and embraces further content in various forms of consciousness, including mystical experiences in different traditions and experiences of full union (with God).

1. The main tenet of the epistemic conception of hallucinations is that we can positively characterise their common makeup - if they share any at all - only in epistemic, but not in metaphysical terms.1 Hallucinations differ from perceptions in that they do not put us into contact with the world in such a way as to enable us to refer to mind-independent objects and acquire knowledge about them. And certain hallucinations are special in so far as they are, in a significant sense, subjectively indiscriminable from perceptions. According to the epistemic conception, these two claims - one being negative and metaphysical, the other positive and epistemic - capture all that can, and need to, be said about what these subjectively perception-like hallucinations have in common.2 The epistemic conception of hallucinations may be partly motivated by drawing attention to the observation that, while there is only one way in which perception can go right, there are many ways in which it can go wrong. Perception goes right just in case it relates us to the external world in the way just mentioned. In all other cases, it goes wrong; and it may fail to establish the required relation on different occasions for very different reasons.

D’Souza claims that near-death experiences (NDE) suggest that consciousness can outlive the breakdown of the body and cannot be explained as the product of dying brains. These experiences can be found in situations where a subject is not near death and have all the characteristics of hallucinations caused by oxygen deprivation. Despite thousands of cases, no one has every come back from an NDE with information that could not have been in their heads originally.

Hypnagogic and hypnopompic experiences (HHEs) accompanying sleep paralysis (SP) are often cited as sources of accounts of supernatural nocturnal assaults and paranormal experiences. Descriptions of such experiences are remarkably consistent across time and cultures and consistent also with known mechanisms of REM states. A three-factor structural model of HHEs based on their relations both to cultural narratives and REM neurophysiology is developed and tested with several large samples. One factor, labeled Intruder, consisting of sensed presence, fear, and auditory and visual hallucinations, is conjectured to originate in a hypervigilant state initiated in the midbrain. Another factor, Incubus, comprising pressure on the chest, breathing difficulties, and pain, is attributed to effects of hyperpolarization of motoneurons on perceptions of respiration. These two factors have in common an implied alien ''other'' consistent with occult narratives identified in numerous contemporary and historical cultures. A third factor, labeled Unusual Bodily Experiences, consisting of floating/flying sensations, out-of-body experiences, and feelings of bliss, is related to physically impossible experiences generated by conflicts of endogenous and exogenous activation related to body position, orientation, and movement. Implications of this last factor for understanding of orientational primacy in self-consciousness are considered. Central features of the model developed here are consistent with recent work on hallucinations associated with hypnosis and schizophrenia.

In this paper, I examine the so-called disjunctive views on hallucinations. I argue that neither of the options open to the disjunctivist is capable of accommodating basic phenomenological facts about hallucinatory experiences and the explanatory demands behind the classical argument from hallucination. A positive characterization of the hallucinatory case is not attractive to a disjunctivist once she is disposed to accept certain commonalities with veridical experiences. Negative disjunctivism glosses the hallucinatory disjunct in terms of indiscriminability. I will argue that this move either renounces to characterize phenomenally the hallucinatory experience or does not take seriously questions about why indiscriminability is possible in the phenomenal realm.

A general definition of consciousness that accommodates most views (Vimal, 2010b) is: “ ‘consciousness is a mental aspect of a system or a process, which is a conscious experience, a conscious function, or both depending on the context and particular bias (e.g. metaphysical assumptions)’, where experiences can be conscious experiences and/or non-conscious experiences and functions can be conscious functions and/or non-conscious functions that include qualities of objects. These are a posteriori definitions because they are based on observations and the categorization.” Non-conscious experiences are equivalent to relevant proto-experiences and nonconscious functions are equivalent to related proto-functions at various levels as these terms are precursors of respective conscious subjective experiences and conscious functions aspect of consciousness. The non-conscious experiences and non-conscious functions may be considered as a part of the definition of mind and/or awareness.