Consciousness refers to one's awareness of their thoughts, feelings, sensations and environment. It is constantly shifting between internal mental states and external focus of attention. For example, focusing on reading and then shifting to a memory or physical sensation. Early psychologists like Descartes and William James influenced theories of consciousness. Descartes viewed consciousness and the mind as interacting with the body to create our experience of the world. James compared consciousness to a continuous and ever-changing stream of thoughts and perceptions. Key concepts around consciousness include it being considered a psychological construct, and differences between views like monism versus dualism that see the mind and body as separate or unified.

1. States of Consciousness