Consciousness

Ancient Greeks

The ancient Greeks provided early speculations on the human mind. Plato was one of the first thinkers to attempt to formulate the definition of what would become known as consciousness. Of course at that time there was no word equivalent that had the wide range in meaning that the word consciousness has in 20th- and 21st-century thought. Therefore the ancient Greeks speculated on what was known as mind.

Plato was one of the first to develop the idea of the mind. He proposed that the mind is something in the head and that objects existed as impressions in the material world. However, he maintained that these impressions were visible forms that are conveyed through what he called “the mind's eye” by a third nature: light. Plato further elaborated that these visible forms were observed by the mind's eye as mental content arranged as geometrical forms. Plato proposed that these geometrical forms were provided by the soul.

Another ancient Greek philosopher who expanded on the early ideas of consciousness was Aristotle, who was a physicalist, meaning that he believed that all things, including human beings, are intrinsically incorporated in a material universe. This is why he thought that the study of the soul (or psyche and to an extent consciousness) would fall within the confines of the science of nature. Aristotle made note of the concept of signals (sight and sound), the transmission of information (those signals reaching the human mind), and in many ways the notion of perception (the mind's realization of those signals).

Aristotle's idea of the mind, in general, supported Plato's idea that mind was something in the head (the brain), and that an object in the material world existed as an extension of time. However, Aristotle proposed that an impression of these objects was received by the sense organs (eyes and ears), and that the impressions received were relayed in a changed state to the mind and were extended throughout time and space.

Early Theories of Consciousness

René Descartes (1596–1650) was another influential thinker on the topic of consciousness. He was also responsible for coining the very famous Latin phrase cogito ergo sum, which in English means, “I think, therefore I am.” While Plato and Aristotle maintained that faculties of the mind and soul could not be outlined or represented by mere terms of physiology, Descartes expanded their ideas into what is know as dualism (or Cartesian dualism). Descartes proposed that the physical world occurs in an extended form in the brain (which is material), but through a particular process it is then condensed into a nonextended form in the mind where thought occurs (which is nonmate-rial). He also believed (much like Plato) that thoughts were produced by the soul, which is also nonmaterial. Therefore, according to Descartes' theory of dualism, the actual process of consciousness involves a material and a nonmaterial component.

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