How to Define Consciousness—and How Not to Define Consciousness

Definitions of consciousness need to be sufficiently broad to include all examples of conscious states and sufficiently narrow to exclude entities, events and processes that are not conscious. Unfortunately, deviations from these simple principles are common in modern consciousness studies, with consequent confusion and internal division in the field. The present paper gives example of ways in which definitions of consciousness can be either too broad or too narrow. It also discusses some of the main ways in which pre-existing theoretical commitments (about the nature of consciousness, mind and world) have intruded into definitions. Similar problems can arise in the way a “conscious process” is defined, potentially obscuring the way that conscious phenomenology actually relates to its neural correlates and antecedent causes in the brain, body and external world. Once a definition of “consciousness” is firmly grounded in its phenomenology, investigations of its ontology and its relationships to entities, events and processes that are not conscious can begin, and this may in time transmute the meaning (or sense) of the term. As our scientific understanding of these relationships deepen, our understanding of what consciousness is will also deepen. A similar transmutation of meaning (with growth of knowledge) occurs with basic terms in physics such as "energy", and "time." Why is it difficult to define consciousness? As George Miller wrote in 1962, "Consciousness is a word worn smooth by a million tongues." Almost 50 years later, little has changed. The term means many different things to many different people, and no universally agreed "core meaning" exists. This is odd, as we each have "psychological data" about what it is like to be conscious or to have consciousness to serve as the basis for an agreed definition. This uncertainty about how to define consciousness is partly brought about by the way global theories about consciousness (or even about the nature of the universe) have intruded into definitions. In classical Indian writings such as the Upanishads, consciousness is thought to be the essence ofĀtman, a primal, immanent self that is ultimately identified with Brāhman—a pure, transcendental, subject-object-less consciousness that underlies and provides the ground of being of both Man and Nature (Sen, 2008). In the classical Western tradition, "substance dualists" such as Plato and Descartes bifurcated the universe, believing it to consist of two fundamental kinds of stuff, material stuff and the stuff of consciousness (a substance associated with soul or spirit). Following the success of the brain sciences and related sciences, 20th Century theories of mind in the West became increasingly materialistic, assuming physical “stuff” to be basic, and consciousness in some way “supervenient” or dependent on the