McLuhan saw media as an extension of self. Basically, technology extends natural human abilities. Technologies are not simple additions to human existence. These technologies change how humans think, feel and act, even the individual's perception and information processing. New technologies have psychological, physical and social effects. "We shape our tools and our tools shape us". McLuhan abstracted four laws of media from his research.
The four laws help describe the properties of each medium or technology:
Enhances
An individual's or organisation's use of technology in a new way extends the reach of body and mind: the car can be seen as an extension of the feet; a microscope as an extension of the eye; an engine an extension of our feet and arms, a library an extension of the mind. 'What does the artifact enhance or intensify or make possible or accelerate?'. (McLuhan)