McLuhan in “Understanding Media” emphasizes the importance of media in human life, how they changed and keeps changing it and invites the reader to analyze the medium as the message, not for its content. Examples of media are the bulb, the print or any new technological inventions. For McLuhan media is anything that extends our capabilities as human beings influencing our way of thinking, interacting and behaving. A medium influences our “sense ratios” (our senses) in fact it uses specific senses to transmit the message for example we read a book through eyes and mind and we watch television with our eyes and ears. McLuhan defines media as “extensions of ourselves” and the cause of positive and negative changes in human behaviors and societies. For example, the introduction of new technologies brought a change in the interaction between humans which eliminated jobs but at the same time created roles for people. Another example is the railway which doesn’t introduce only movement or transportation but increased the speed of human functions creating new cities and new activities. So society is affected not merely by the content of the medium but by its characteristics, such as the electric light which controls the form of human action and activities. It is thanks to the electric light that men can operate or play baseball in the dark. The medium in this case eliminates space and time. Another example is the impact and the role of the tv had on the society, not because of the kind of shows it showed (its content) but because of its characteristics. Furthermore, as a movie is a combination of different medias such as speech, music.. The same is Cubism, where different patterns, textures, lights were used. The final work of art was a fragmented representation of something (from the top, from the side or the bottom) that let the viewer to receive the message as an whole (“drops the illusion of perspective in favor of instant sensory awareness of the whole”) through different media. 

McLuhan affirms that the machine technology brought fragmentation and decentralization (which is centralist and superficial) while the automation technology brought the opposite. McLuhan defines alphabet as a basic mechanical technology in which the language has been broken in twentysix characters that we can arrange to create words and express thoughts. Before the written language men had to physically communicate through spoken word. The introduction of the electric technology such as the telegraph brought a speed diffusion of the written text in few seconds instead of weeks. 

The content of any medium is another medium, for example for the telegraph is the print, for the print is the written word, for writing is the speech, for speech is a process of thought. “An abstract painting represents direct manifestation of creative thought processes as they might appear in computer designs.”   

At a certain point McLuhan introduces the analyses of Arnold Toynbee of the power of the medium and the concept of “etherialization”. He affirms that our personal opinion or perception of a medium produces a different effect. He introduces the third dimension or private point of view comparing it to the Narcissus fixation, in which the medium brings to the alienation of the man. 

As Werner Heisenberg, in The Physicist’s Conception of Nature, underlines technical changes brings changes not only in the way we behave but also in the way we think and value. One of a possible psychological effect of technologies is the demand for them. The need of constantly have the radio or tv on not for its content, but because we feel the urge of using the senses that are available. “Electric technology is directly related to our central nervous system”. The dependence of the man to technology created a kind of enslavement, but at the same time pushed the fragmentation and the rebellion as a technique of achieving security. 

McLuhan recognizes the art as immune to the technology and able to provide immunity. The artist has integral awareness and he can correct the sense ratios before the influence of new technology.