Definition and scope of consciousness

Summary

Consciousness is generally defined as awareness of something internal to oneself (one’s own states, thoughts, feelings) and/or awareness of objects and states in the external environment. Historically, the term often referred to an “inner life” accessible through introspection—private thought, imagination, and volition—but modern usage commonly broadens it to include forms of cognition and experience such as perception, feeling, metacognition, and self-awareness. There is also a medical usage of the concept, for example to help distinguish coma from other impaired states. The scope of consciousness is debated because there is no consensus on what exactly should count as consciousness or how to define it in a way that is scientifically usable. Traditional and everyday meanings vary (e.g., inward awareness vs. perception of the physical world; mental entities vs. mental activities; conscious vs. unconscious). Philosophers often distinguish different aspects, such as introspective consciousness (what can be known via introspection) versus phenomenal consciousness (the “what it is like” character of experience). This definitional difficulty affects research: scientists and philosophers disagree on whether consciousness can be treated as a well-defined scientific concept, and on what evidence (reports, behavior, neural measures, or “what it is like”) should be used to study it.

Key Points

• 1

  Consciousness is commonly characterized as awareness of internal states and/or external surroundings, but its exact definition and boundaries are contested.

• 2

  Modern discussions broaden consciousness beyond introspection to include cognition, experience, and self-related awareness, while medical and scientific contexts add further operational distinctions.

• 3

  Philosophical work highlights multiple dimensions of consciousness (e.g., introspective vs. phenomenal), and the lack of consensus complicates scientific measurement and study.