Marshall McLuhan was an unknown Canadian professor of English until he published Understanding Media in 1964. The book became a best-seller and catapulted him to international prominence as a media analyst. He spent the rest of his life writing and lecturing on his key theme: the effects of technology on human beings. He died of a stroke in 1980, decades before many of his predictions about the internet and online culture were realized. He is best remembered for the expression "the medium is the message" and the term "global village."


We often use the word media as a shorthand for mass communication media that bring us news and information – like newspapers, radio, and television. In this usage, the term refers both to its technologies and to the industries that provide much of the content through those technologies.

According to McLuhan, all forms of technology function as media, not just those that communicate information. All human innovations, whether material or immaterial, mediate – or stand between – our physical selves and our consciousness of, and interaction with, the world around us. All forms of technology are media through which human perception and experience are transformed.

Laws of Media

All media – that is, all inventions, artifacts, and ideas – have these four effects:

  • they extend our body, mind, and being

  • as they extend some human ability they simultaneously obsolesce some other form of experience

  • they retrieve and enhance a sense or skill that was obsolesced earlier and the current media do not stimulate

  • when pushed to their limit they have a reverse effect, producing opposite or complementary forms

These effects occur simultaneously whenever a new technology is put into use. Some effects may take years to make themselves apparent but the four properties are inherent in all media.


Every medium enhances or intensifies some human attribute, ability, or experience:

  • clothing is an extension of skin because it enhances the function of our skin in protecting our internal organs

  • the wheel is an extension of the foot because it accelerates the movement of our feet in physical space

  • language is an extension of thought because it enables thoughts from within our own mind to be conveyed to others

  • writing is an extension of human memory because it allows us to recall ideas that were expressed in the past

  • the phone is an extension of the range of the voice and the reach of the ear

  • news is an extension of the focus of our attention and our involvement with others

  • a movie is an extension of the imagination and the communication of ideas and emotions

  • the internet is an extension of the central nervous system and the brain

All media extend the reach of body and mind. They enable us to do more than our bodies could do on their own, but they are not merely tools. They are extensions of some physical, social, psychological, or intellectual function of humans. They amplify, accelerate, promote, or push to the forefront of our attention some human characteristic.

McLuhan uses the concept of figure-ground to illustrate how media bring different social elements into focus, allowing others to recede in importance. Figure is any consciously noted element of a structure or situation, while ground is the rest of the structure that goes unnoticed. Figure occupies the foreground of our attention while ground occupies the background.

Extension turns an element of ground into figure or further intensifies something already figure.


Because there is equilibrium in sensibility, whenever one area of experience is heightened or intensified, another area is diminished or dormant. The introduction of a new medium always removes or reduces the role of some other medium or form of experience.

The invention of the car, for example, obsolesced the use of horse and carriage. The widespread use of cellphones has greatly reduced the need for telephone booths and landlines. In the 20th century, the camera obsolesced portrait and landscape painting; and in the 21st century, the smartphone camera has obsolesced privacy and anonymity.

Obsolesced forms do not disappear completely but can reappear in the form of art or as a source of nostalgia. The phenomenon of hot air ballooning as a form of recreation illustrates this idea. In the age of supermarkets and slick packaging, a farmer's market becomes a source of intense nostalgia and a tourist attraction.

Digital music, email, and online games have obsolesced record collecting, letter writing, and board games. But these activities continue to flourish as niche interests and hobbies. The old technologies are not eliminated altogether but lose their initial usefulness and function.

Obsolescence renders a former situation impotent by displacement: figure returns to ground.


Humans have a limited set of senses and motor skills. The current media stimulate and reinforce only some of them. Since the number of senses and skills is limited, an older, outdated medium had probably addressed this sense or skill before. A new medium will "retrieve" and enhance a sense or skill that the current media do not stimulate.

All media restore or revive some form of experience that predominated in our past and had been lost or dormant. An older, previously obsolesced action or service is brought back into play and becomes an essential part of the new form.

The invention of the radio, for example, retrieved the function of a town crier making public announcements. An airplane recreates in the sky the experience of rafting, while a photograph brings back a visual point of view from the past in a new way. A car, with its metallic shell, recalls a knight on horseback, while clothing retrieves the protection of the womb.

Retrieval puts something long obsolete back into service: ground becomes figure through the new situation.


When a new medium is introduced, the content is figure, while the new environment is ground. But figure and ground are in a continual state of abrasive interplay. The relationship of figure and ground is not static and may "flip" if pushed too far. A medium can "overheat" and reverse into an opposing form when pushed to its limit.

Every technology has within itself the seeds of its reversal. When a medium is pushed beyond its capacity, it risks reversing its users' enthusiasm for its original benefits into complementary or even opposite forms. All media when stressed by overuse produce reverse effects that may be unwanted or harmful.

For example, in the technology of industrialization, human industry and commerce are figure and the natural environment is ground. However, when pushed beyond its capacity the model flips: pollution and ecological disaster become figure while the culture of factory work and consumerism recede into ground. The mobility made possible by the car flips into immobility when the car is pushed beyond its limit in the form of gridlock or collision.

Psychoactive drugs when taken in excess can lead to loss of consciousness instead of enhancement of consciousness. Credit cards extend the consumption of goods and services but when overused can reverse into bankruptcy and destitution.

Reversal involves dual action simultaneously, as figure and ground reverse position and take on a complementary configuration. Figure becomes ground by overload.


The four Laws of Media derive from two figure-ground dualisms. McLuhan illustrates the laws visually in the form of a tetrad (set of four) which links the four effects of media:


Opposing quadrants form a complementary relationship: Extension is to Reversal as Retrieval is to Obsolescence, and Extension is to Retrieval as Reversal is to Obsolescence.


A human attribute, ability, or experience that is intensified, amplified, accelerated, promoted, or pushed to the forefront




An opposite or complementary form produced when the medium is pushed to the limit of its potential or beyond its capacity




A revival, restoration, or reappearance of some tendency, behaviour, or thing from the past that had been lost or less active




A removal, disappearance, displacement, weakening, or making unnecessary of something




The effects on the left side of the tetrad – Extension & Retrieval – tend to be more easily visible, because they are figure. The effects on the right side – Reversal & Obsolescence – are not always as obvious or apparent, especially in the early use of a medium, because they are ground.

A tetrad of technology (medium) itself reveals the effects common to all media:


body, mind, and being

unintended consequences and harm

human ingenuity and creativity

the natural world

The tetrad is intended as a creative tool, a trigger for thought and investigation, enabling us to analyze the patterns of effects produced by different technologies. The tetrad can be applied to all types of media: physical objects as well as ideas, concepts, and belief systems – anything created by human beings.

By applying McLuhan's laws to any technology – especially a new technology – we can better understand how to protect ourselves from the power it may have over us.

The Medium is the Message

McLuhan's oft-repeated expression "the medium is the message" is meant to suggest that the real "message" of any medium is the change in scale, speed, or pattern that it causes in human relations and activities. These effects occur independent of both the content of the medium and the intention of its users.

The railway, for example, accelerated and enlarged the scale of previous human functions, creating totally new kinds of cities and new kinds of work and leisure. This happened whether the railway functioned in a tropical or a northern environment, and is quite independent of the freight or content of the railway medium.

Tthe principal effect of any technology is not the information it carries – what we usually think of as the "content" or "message" – but rather the new environment of services that it brings into being. While the content draws our attention, the new environment transforms our perceptions and behaviour subliminally. The new environment is a process or set of actions and behaviours that the medium necessitates, not a container. It is an ecosystem of services and disservices brought into being with the adoption of a new medium.

The invention of the car, for example, not only enabled people to travel great distances over land very quickly – something not easily done before – but it lead to the construction of highways and the growth of suburbs. The car also introduced into our lives: gas stations, car accidents, drive-in movies, exhaust fumes, auto racing, etc.

So the principal effect of the car is not the greater travel that it fostered, but the widescale changes to our physical landscape and social organization that it brought into being. The message here can only be understood if figure (the car) and ground (the environment in which the car is used and which it produces) are analyzed together.

The method of delivering information influences people and society far more than the information itself. A story, for example, has different meanings depending upon whether it is related orally, written in a book, acted out on the stage, heard on radio, presented on film, viewed on television, or depicted in a comic book. The form of any medium transforms its message.

Media work in pairs, one medium "containing" another – and that one can contain another, and so on. The contained medium becomes the content or message of the containing one. The content of any medium is always an older medium. When a medium first appears, it uses the content of another medium exclusively for its content until its users have learned to exploit the new medium to develop new forms of expression.

For example:

  • the content of cinema is theatre
  • the content of theatre is narrative
  • the content of narrative is language
  • the content of language is thought, which ends the chain of media because thought is an innate process

The new environment created by a medium enables us to do something we could not do before but also shields our awareness – "numbing" us – from some of the medium's adverse effects. This numbness protects our psyche when it is suddenly exposed to the new stresses that the medium creates. In electric technology, numbness is a self-amputation of the nervous system, which becomes extended by the new medium. It is because of this self-induced numbness that the effects of media are often counterintuitive and subliminal.

McLuhan's core idea is that a society's technology drives the development of its social structure and cultural practices. Technology in general and communication media in particular define the terrain of human behaviour and thought so completely as to be, in effect, our real environment – our second nature, in the fullest sense.

Media are not passive channels of information but exert great power by creating hidden environments that act abrasively and destructively on older forms of culture, and as a consequence create new social patterns. With the continued use of certain media, a flip occurs and humans become extensions of their technology, and as a result societies come to imitate their technologies.

Art as Anti-Environment

Each new medium produces a new cultural environment that is invisible, while making visible the one of the previous culture. The present is always imperceptible because it saturates the whole field of attention. An environment becomes fully visible only when it has been superseded by a new environment, so we are always one step behind in our view of the world, terrified of confronting the present head-on.

Every cultural era proceeds forward while looking backward, viewing the present through a "rear-view mirror." When faced with a totally new situation, we tend always to attach ourselves to the objects and flavour of the most recent past. The dominant technologies of one age become the games and pastimes of a later age.

The only person who can see the present directly is the artist, whose anti-environment draws our attention and enables us to see and understand the present more clearly. Art, like games, is a translation of experience. What we have already felt or seen in one medium we are suddenly given in a new kind of material.

Art as an anti-environment is an indispensable means of perception by bringing the unconscious environment to conscious attention. The task of art is to correct the bias that technology imposes. Art prevents us from becoming too adjusted to our environments and becoming the servants of those environments. Art at its most significant acts as an early warning system that can always be relied on to tell the old culture what is beginning to happen to it.

Sense Ratios

McLuhan uses the word media to refer to all forms of technology but asserts that communication media in particular have unique and far-reaching effects on society and culture. Technologies of communication differ greatly in how they make use of our senses.

The introduction of a new medium alters what McLuhan calls our sense ratios: the relationships among the five physical senses. No sense operates in isolation. Human consciousness involves all the senses at once but our individual senses vary in the complexity of the perceptions we get through them. Media extend our use of certain senses while simultaneously diminishing our use of other senses.

People adapt to their environment through a certain balance of their senses. When media combine, they establish new ratios among themselves just as they establish new ratios among the senses. The primary medium of the age brings out a particular sense ratio, a reprogramming of social life. What had appeared lucid before may suddenly become opaque, and what had been vague or opaque will become translucent.

Acoustic Space

Before the invention of writing, communication involved all the senses simultaneously, speaking being accompanied by gestures and requiring both listening and looking. People led a complex, kaleidoscopic life, drawn to each other in a tribal mesh. Humans lived in what McLuhan calls acoustic space, the environment of the spoken word.

The ear favours no particular point of view, forming a seamless web around us. We hear sounds from everywhere, all around us, without ever having to focus. We can't shut out sound automatically, we are simply not equipped with earlids.

Acoustic space is boundless, horizonless, and charged with emotion. It is without fixed boundaries, space made by the content itself, not space containing the content. It is not boxed in but dynamic, always in flux, creating its own dimensions moment by moment.

The key characteristic of acoustic space is that it engages multiple senses at the same time. It does not demand that objects be dissected to be understood; rather, the multiple parts co-exist simultaneously. To understand acoustic space, you must perceive all of it, not focus on one part.

In other words, acoustic space demands that you apprehend figure and ground simultaneously, that the senses work together. Acoustic space was dominant in preliterate societies in which all the senses were involved in communication simultaneously.

Visual Space

The immediacy and rich complexity of preliterate communication was reduced by the alphabet to an abstract visual code. Technologies that emphasize the eye over the other senses produce the impression that things in a visual plane are connected in the same way that, when you read, words build on each other by following rules of grammar and logic. These rules are the product of a way of thinking that links things that otherwise do not necessarily have any connection. This tendency, to link things together, presupposes that things are made up of parts. To understand the whole, and the connections therein, you must dissect the parts; hence, objectivity becomes a value.

When writing was introduced, it did not simply record oral language; it was an entirely new language. The introduction of writing transformed the environment into something bounded, structured, and made up of connected parts. Humans began to conceive of the world as being rational, logical, with events and ideas proceeding in a linear progression. The written page – with its edges, margins, and sharply defined letters in consecutive rows – introduced the era of visual space.

The book is basically an extension of writing's abstract code with an even more uniform, linear order. Using this linear order a book's code proceeds from subject to verb to object, from sentence to sentence, from paragraph to paragraph, from chapter to chapter. An event lasting only a brief moment in the real world may require many pages of description in a book for one to "get the full picture." A book must restructure reality in linear form. Books present an organized, logical, progression of words and pictures in a word-ordered world.

After the invention of the printing press with movable type in China in the 11th century and in Germany in the 15th century, reading became the primary means of communication for the first time in history. The sense of sight was greatly intensified in its importance compared to the other senses. Where the world of the ear is a world of simultaneous relationships, visual space is an organized continuum of a uniform, connected kind. It is the space perceived by the eyes when they are abstracted or separated from the activity of the other senses.

Whereas acoustic space is a natural environmental form, visual space is a human-made artifact. This is the predominant form of most industrialist technologies, such as steam power, reading, and writing. Visual space was dominant in the West from the 15th century to the 20th century, when reading and writing were supplanted by electric forms of communication.

The printed word gave rise to a culture in which individualism and uniformity were promoted. The proliferation of books increased the spread of information exponentially, while giving rise to linear habits of thought and a private point of view. Reading fostered in people a detached, logical, and compartmentalized relationship with the world around them.

Global Village

The invention of the telegraph in the 19th century enabled – for the first time – instantaneous communication over long distances. Electricity ended sequence by making things instant. Switching over to circuitry from mechanical moving parts and wheels produced an enormous increase in the amount of information being shared. The harnessing of electricity in the 20th century significantly altered our sense ratios, and acoustic space once again became dominant.

Television reawakened our tactile sense, diminishing the visual sense relied upon in a purely print culture and replacing it with an all-encompassing sensory experience. Although there is no contact between the skin of the viewer and the TV, the eye is so much more intensely engaged by the TV screen than by print that the effect is the same as that of touching. McLuhan considers television audile-tactile precisely because it engages several senses at the same time: it creates an acoustic space.

In the early 1960s, McLuhan claimed that the visual, individualistic print culture was being brought to an end by what he called "electronic interdependence," when electric media replace visual culture with a new aural/oral culture. In this new age, humankind moves from individualism and fragmentation to a collective identity with a "tribal base." The tribe is completely connected and all of its members have direct access to one another.

In the present era, electronic media are the primary means of communication. Our visual, auditory, and tactile senses are fully involved. Knowledge is once again synthesized instead of being splintered into specialties. Whereas the predominant organizing principle of print culture was linear – introduction, development, and conclusion – contemporary culture is characterized by repetition, juxtaposition, overlap, and disjunction. Ours is a brand new world of simultaneity, a global village in which everyone is connected to everyone else all the time.



before the 5th century BC
• era of acoustic space: the spoken word was the primary means of communication so hearing was believing

• in preliterate societies people lived in a seamless web of tribal kinship

• people were guided by primordial intuition and terror, and lived lives of passion and spontaneity


Scribal era: 5th century BC to 15th century AD

Gutenberg era: 15th century to 20th century
• era of visual space: the printed word and the eye were dominant

• the phonetic alphabet forced the magic world of the ear to yield to the neutral world of the eye

• the invention of the printing press with movable type in the 11th century in the East, and in the 15th century in the West, made possible the portable book, which people could read in privacy and in isolation from others

• literacy conferred the power of detachment and non-involvement

• reading and writing fostered individualism, specialism, and fragmentation, which spurred the development of mathematics, science, and philosophy

• nations and nationalism arose only through phonetic literacy with print technology; before that, the dominant relationships were between families, tribes, and clans


since the 20th century
• era of acoustic space: full sensory involvement, especially the tactile sense

• TV extended the sense of touch by drawing in the whole person, with all of his or her senses, into an involvement with the content of the medium

• in the 21st century, electronic media like the internet and smartphone have retribalized us, returning us to a tribal village on a global scale

• electric technology foster unification and involvement

Hot & Cool Media

McLuhan draws a distinction between media that provide a lot of sensory information, labelling them hot, and media that provide comparatively little sensory information, describing them as cool. Hot and cool media differ in the degree to which the user actively participates in decoding the medium's content.

Hot media, which usually enhance a single sense in high-definition, "boil over" with data, requiring little involvement on the part of the user. A photograph, for example, provides so much visual data that a person does not need to exert much effort in filling in the details of the image.

Cool media, on the other hand, require more effort on the part of the user to determine meaning. Television, for example, requires the viewer to connect the pixels instantaneously to give meaning to the otherwise indistinct images on the screen. (Advances in television resolution and size have "heated up" a previously very cool medium.) Comics, which due to their minimal presentation of visual detail, are even cooler, requiring a high degree of effort to fill in details that the cartoonist may have intended to portray.

McLuhan's use of the terms hot and cool are not intended to force media into binary categories. Hot and cool exist on a continuum, more correctly measured on a scale than as dichotomous terms. The concept is especially useful for comparing pairs of media that have a similar type of function or purpose.

Generally, hot media work even better when over-extended while cool media can "overheat" and become less effective under such conditions. Although most hot media create hot responses, a hot medium can be used to stimulate the participatory quality of a cool medium like television and vice versa. A play presented on radio has a cooler impact than it would in a theatrical performance, because it forces us to visualize the characters. A face-to-face argument creates a hot experience in the cool medium of human talk.

usually emphasize one sense over the others in high-definition their low-definition often require the use of multiple senses to "get the full picture"
often emphasize the visual or require vision-like focus tend to emphasize the audile-tactile
favour analytical precision, quantitative analysis and sequential ordering require the perception of abstract patterning and simultaneous comprehension of all parts
linear, logical, controlled,
unified, holistic, creative,
low in participation,
foster detachment and privacy,
high in participation,
foster involvement and engagement,
can be "overheated" or overextended, and this intensification can make them more effective overheating usually makes them less effective
photograph sketch
paper stone tablet
cinema television
Facebook Twitter
lecture seminar
classical music popular music
writing speech
painting cartoon
YouTube Instagram
book dialogue
radio telephone
phonetic alphabet ideographic script
email texting
the waltz the twist
Ultra HD low-res streaming
prose poetry


McLuhan's approach to understanding media was to refuse to have a single viewpoint about anything he observed. To fully understand something, he believed, it has to be looked at it from different points of view. Rather than offering a static theory of technology, he would probe, or explore, his environment in an attempt to discover patterns and connections among media and their effect on our culture. He sought patterns that would lead to understanding of constantly changing processes, rather than to frozen categories, like "good" or "bad," that lead merely to judgments based on past experience.

Many of his greatest insights were derived from abandoning all assumptions and preconceptions, relying only on percepts – unmediated perceptual impressions – to discern connections. He wrote: "to cognize is percept, to re-cognize is concept." Percepts enable a plurality of views, while concepts require a particular and intentional filtering of the available data.

McLuhan used satire, paradox, and hyperbole as probes to stimulate fresh discovery, rather than conventional academic methods which merely consolidate old knowledge. This approach allowed him to investigate a wide range of topics without necessarily committing himself to conclusions or testing his hypotheses scientifically.

Below are some of McLuhan's observations about media derived from probes:

  • Language is humankind's first technology for extending consciousness.

  • The humanly contrived environment of electric information and power has taken precedence over the old environment of nature. Nature is now the content of our technology.

  • The 20th century was the age that moved beyond invention to studying process – whether in literature, painting, or science – in isolation from product.

  • Effects are perceived, whereas causes are conceived. Percepts are unique experiences of direct encounter with present existence. Concepts are convenient packages of similar percepts of past experience that automatically convert the present into rear-view images.

  • The clock is a machine that turns out the uniform products of seconds, minutes, and hours on an assembly-line pattern, separating time from the rhythm of human experience.

  • When people are working, they are partially involved. When totally involved, they are at play or leisure. To be at leisure means that all the human faculties are developed to their utmost, running at full tilt with ease.

  • The TV image is the first technology to project or externalize our tactile sense.

  • One of the effects of living with electric information is that we live habitually in a state of information overload. Because there is always more than we can cope with, we rely on pattern recognition to make sense of all the data.

  • Madison Avenue is a very powerful aggression against private consciousness, demanding that we yield our private consciousness to public manipulation. Once we have surrendered our senses and nervous systems to the manipulation of those who would try to benefit from taking a lease on our eyes and ears and nerves, we don't really have any rights left.

  • The Achilles' heel of "civilized" people is propaganda. They will believe anything as long as it has a good enough sell. Propaganda blankets perception and suppresses awareness, making the counter environments created by the artist indispensable to survival and freedom.

  • World War I was a railway war of centralization and encirclement. World War II was a radio war of decentralization concluded by the Bomb. World War III is a guerrilla information war with no division between military and civilian participation.