Historical Theories of Consciousness

Mayan and Incan Theories of Consciousness 

First appearing in the historical records of the ancient Mayan and Incan civilizations, various theories of multiple levels of consciousness have pervaded spiritual, psychological, medical, and moral speculations in both Eastern and Western cultures. Consciousness can be defined as human awareness to both internal and external stimuli. Because of occasional and sometimes substantial overlap between hypotheses, there have recently been attempts to combine perspectives to form new models that integrate components of separate viewpoints.

The Ancient Mayans were among the first to propose an organized sense of each level of consciousness, its purpose, and its temporal connection to humankind. Because consciousness incorporates stimuli from the environment as well as internal stimuli, the Mayans believed it to be the most basic form of existence, capable of evolution. The Incas, however, considered consciousness a progression not only of awareness but of concern for others as well.

John Locke on Consciousness 

John Locke, a 17th-century philosopher, was one of the first to speak and write on consciousness. He believed that our identity was tied to our consciousness, which he essentially defined as what passes through a man’s mind, or memories. He also asserted that our consciousness is not tied to our physical bodies, and that it can survive even after our physical bodies die. In fact, Locke held that consciousness could be transferred from one soul to another. 

René Descartes on Consciousness 

René Descartes also addressed the idea of consciousness in the 17th century. He set out to answer the question of how it is possible that our consciousness, a non-physical thing, can come from our bodies, a physical thing. The explanation he came up with was called Cartesian dualism; in short, consciousness resides within an immaterial domain he called res cogitans (the realm of thought), in contrast to the domain of material things, which he called res extensa (the realm of extension). He suggested that the interaction between these two domains occurs inside the brain.

Sigmund Freud on Consciousness

While Eastern perspectives on consciousness have remained relatively stable over the centuries, fluctuations in theory have come to define the Western perspective. One of the most popular Western theories is that of Sigmund Freud, medical doctor and father of psychoanalytic theory. Freud divided human consciousness into three levels of awareness: the conscious, preconscious, and unconscious. Each of these levels corresponds and overlaps with Freud's ideas of the id, ego, and superego. The conscious level consists of all the things we are aware of, including things we know about ourselves and our surroundings. The preconscious consists of things we could pay conscious attention to if we so desired, and is where many memories are stored for easy retrieval. Freud saw the preconscious as comprised of thoughts that are unconscious at the particular moment in question, but that are not repressed and are therefore available for recall and easily capable of becoming conscious (for example, the tip-of-the-tongue effect). The unconscious consists of things that are outside of conscious awareness, including many memories, thoughts, and urges of which we are not aware. Much of what is stored in the unconscious is thought to be unpleasant or conflicting; for example, sexual impulses that are deemed unacceptable. While these elements are stored out of our awareness, they are nevertheless thought to influence our behavior.

Freud's levels of consciousness

This figure illustrates the respective levels of the id, ego, and superego. The part above water is known as the conscious level; the top level of waves just below the surface and above the white line is the preconscious level; and the bottom level is the unconscious.

Modern Theories of Consciousness

While Freud's theory remains one of the best known, various schools in the field of psychology have developed their own perspectives, which we will explore below. It is important to note that these perspectives are not necessarily mutually exclusive, just different approaches to the same questions. 

Developmental Psychology on Consciousness 

Developmental psychologists view consciousness not as a single entity, but as a developmental process with potential higher stages of cognitive, moral, and spiritual quality. They posit that consciousness changes over time, in quality and in degree: an infant's consciousness is qualitatively different than a toddler's, a teenager's, or an adult's. Abnormal development also affects consciousness, as do mental illnesses.

Social Psychology on Consciousness 

Social psychologists view consciousness as a product of cultural influence having little to do with the individual. For instance, because different cultures speak different languages, they also codify reality differently. That difference in codification leads to differences in the experience of reality, and therefore of consciousness. Language is the main mechanism for transmitting a mode of consciousness, and an analysis of language can to some extent reveal the mentality of people who speak that language.

Neuropsychology on Consciousness 

Neuropsychologists view consciousness as ingrained in neural systems and organic brain structures. A major part of the modern scientific literature on consciousness consists of studies that examine the relationship between the experiences reported by subjects and the activity that simultaneously takes place in their brains—that is, studies of the neural correlates of consciousness. The hope is to find activity in a particular part of the brain, or a particular pattern of global brain activity, that will be strongly predictive of conscious awareness. Several brain-imaging techniques, such as EEG and fMRI, have been used for physical measures of brain activity in these studies.