Kinds and Concepts of Consciousness

Consciousness names several phenomena that normally travel together and can come apart. A person may be awake but unaware of an object, discriminate a stimulus without being able to report it, or experience something without reflecting on themselves as the subject. Experimental results and philosophical arguments become equivocal when they establish one of these conditions and conclude another.

This page supplies the taxonomy used throughout the folder. Its central distinction is between access consciousness, defined by availability to cognition and control, and phenomenal consciousness, defined by what an experience is like for its subject. Neither should be treated as the meaning of the word without qualification.

Creature and state consciousness

A creature is conscious when it is awake or sentient rather than dreamlessly asleep, anaesthetised, comatose, or dead. This is a condition of the organism. A mental state is conscious when the subject is conscious of or through that state. An awake creature has many unconscious states; a sleeping creature may undergo a conscious dream.

Clinical measures of level of consciousness usually concern the creature: arousal, responsiveness, and organised wakefulness. Philosophical discussions of experience usually concern states. Moving between them creates bad inferences. Restoring wakeful behaviour may not restore every conscious content, and proving that one stimulus was unconsciously processed does not show that the creature was unconscious.

Transitive and intransitive consciousness

Intransitive consciousness is being conscious, full stop. Transitive consciousness is consciousness of something: the cup, a pain, one's breathing, or the thought that time is short. A state can make one conscious of an object without the object itself being mental.

Transitive consciousness raises intentional questions. Hallucination is consciously as of an object even when no such object is present. A bodily pain seems both to have a felt character and to present a location or disturbance. The distinction therefore connects consciousness to representation without identifying the two.

Access and phenomenal consciousness

Ned Block distinguishes two notions:

• A content is access-conscious when it is poised for reasoning, deliberate action, verbal report, and flexible control.
• A state is phenomenally conscious when there is something it is like for the subject to be in it.

Access is functional: it is defined by what information can do within a system. Phenomenality is first-personal: it concerns the character of undergoing the state. The introduction uses this distinction to keep consciousness apart from intelligence and cognition.

Whether access and phenomenality can dissociate is disputed. Overflow arguments claim that perceptual experience contains more detail than working memory and report can access. Opponents argue that apparent richness reflects accessible gist, partial awareness, and rapid reconstruction rather than inaccessible phenomenal detail. Blindsight supplies the reverse-looking case: above-chance visual discrimination with little or no reported visual experience. Its force depends on whether residual degraded experience and response criteria have been excluded.

The distinction remains useful even if perfect dissociation is impossible. A theory must say whether it explains availability, phenomenal character, or a relation that makes them necessarily co-occur.

Monitoring and self-consciousness

A state may be conscious without the subject explicitly thinking about it. Higher-order awareness is awareness of one's own mental state; self-consciousness can mean awareness of oneself as the subject, sensitivity to how one appears socially, or the capacity to represent oneself across time. These are not one capacity.

An animal may feel pain without applying a concept of pain or representing itself as the owner. Conversely, a system may maintain an accurate self-model and report its internal states without those represented states being phenomenally conscious. This is why metacognitive accuracy is evidence relevant to consciousness, not a definition that settles it.

Wakefulness and responsiveness

Wakefulness is neither sufficient nor necessary for every target notion. Absence seizures and automatisms can preserve open eyes while disrupting access. Dreams can be phenomenally conscious without responsiveness to the environment. Locked-in syndrome can preserve wakeful awareness while blocking nearly every ordinary response.

Responsiveness is therefore a measure with bridge assumptions:

$$\text{response}+\text{intact motor and report channels}⟹\text{available information}.$$

Failure to respond may reflect absence of experience, failure of comprehension, attention, memory, motivation, or motor output. Covert-command paradigms and convergent physiological measures reduce uncertainty but do not turn responsiveness into the essence of consciousness.

Contents, qualities, and modes

Conscious states vary along at least three axes.

• Content: what the experience represents, such as a red apple or a pain in the foot.
• Character: what undergoing it feels like, including colour, intensity, affect, and bodily orientation.
• Mode: whether the content is perceived, imagined, remembered, desired, or thought.

Two states may share content while differ in mode: seeing a red apple differs from imagining one. Two experiences may share representational accuracy while differ in character: blurry and sharp vision can represent the same scene. A theory that reduces character to content must explain these apparent differences rather than assume the axes coincide.

State consciousness and report

Report is powerful evidence because subjects can normally use conscious information in speech and action. It is not constitutive by default. Reports depend on attention, memory, confidence, concepts, language, and motor control. Explaining those mechanisms may explain access while leaving phenomenal consciousness disputed.

No-report paradigms seek neural contrasts that avoid explicit response, using eye movements, pupil changes, or involuntary physiological signatures. They remove some report confounds while adding assumptions about what the indirect marker tracks. The method page gives the general rule: preserve the observation, state the bridge, and test rival mechanisms.

Operational definitions

An operational definition specifies how a variable is measured. It does not necessarily give a metaphysical analysis. Defining consciousness for one experiment as accurate report above a confidence threshold can be excellent methodology if the target is access. It would beg the question if used to prove that unreportable experience is impossible.

Different operations may target different constructs:

Disagreement among measures can reveal that the original category was composite rather than that one instrument simply failed.

Minimal and richer notions

Sentience is often used for the capacity for valenced experience, especially pain and pleasure. Phenomenal consciousness is broader and includes neutral experience. Sapience concerns reasoning or wisdom; self-consciousness requires some form of self-representation. Personhood adds normative criteria. None should be inferred from another without argument.

This matters for animals, infants, patients, and machines. Moral caution may be driven by sentience even where reflective self-consciousness is absent. Sophisticated reasoning may occur without evidence of valence. A broad word such as "conscious" should not hide which threshold carries the practical consequence.

Assessment

The taxonomy is not a neutral dictionary. Higher-order theories make monitoring constitutive; workspace theories emphasise access; phenomenal-first views treat what-it-is-like as explanatorily prior. The point of separating the concepts is to show where theories disagree rather than settle the disagreement by definition.

The next page examines the property at the centre of the dispute: phenomenal character and qualia.

Selected references

• Bayne, Tim. The Unity of Consciousness (2010).
• Block, Ned. "On a Confusion about a Function of Consciousness" (1995).
• Chalmers, David J. "The Conscious Mind" (1996).
• Rosenthal, David M. Consciousness and Mind (2005).