There may be another reality to make fiction of the truth we think that we have arrived at. (Christopher Fry)
The 'real' world is the material world of our bodies, our social environment, other forms of life and the physical universe of energy and matter. The real world is the world we know through our senses - seeing, hearing, tasting, touching and smelling. The information from these senses, together with the thought and emotions that arise in our mind are collectively known as phenomenon. They are presented to and recognized by our consciousness in the process called perception. From them we construct our mental model of the real world.
How real is this real world? Wondering about whether we might be living in some form of artificial reality is not an uncommon idea. In the film ‘The Truman Show’ Truman Burbank lives in the peaceful town of Seahaven. What Truman does not know is that Seahaven exists inside an artificial biosphere from which a live TV show is broadcast 24 hours a day. Everyone in the town except Truman is an actor. Truman has been raised from birth in New Haven and does not know that his whole life has been a never-ending soap opera.
The philosopher Daniel Dennet uses another variation on the above theme to question our assumptions about reality. As part of a thought experiment Dennet asks us to suppose that an evil scientist has removed our brain from our body while we slept and put it into a vat where he can keep it alive. The brain is wired up so that signals can be fed in to imitate all the senses and we are fooled into thinking that we are still living in the real world. Dennet himself rejects this as a serious proposition on the grounds that to do the job effectively would require almost infinite computing power. However, there is no way to prove that it has not happened, to prove that the external world is not just a virtual reality.
In a similar vane Descartes, the seventeenth-century French philosopher, resolved to reject as false everything in which he could imagine the least doubt, in order to see if there was anything left that was beyond doubt. This led to his famous assertion 'cogito, ergo sum' - 'I think therefore I am'. From this position Descartes tried to prove the existence of an omnipotent god. His argument was based on the grounds that we could imagine such a perfect being only if one of them existed to put the idea into our heads. Such attempts to use reason to prove an objective truth are bound to fail (see the chapter on Truth) and Descartes case for the existence of god long ago fell into disrepute. Ironically, today Descartes is popularly seen as the champion of the view that we can be certain of nothing beyond our own conscious awareness.
Idealism is the name given to the philosophy that what we know of the external (material) world is in some way created by our mind. It argues that to assume what we perceive has real substance is to jump to an unjustified conclusion. It is impossible to show that anything exists outside the mind.
Zen Buddhism subscribes to a similar doctrine called "Mind Only", in which it is argued that perception creates the illusion of outer objects from a basic "Storehouse Consciousness". Other Eastern religions and philosophies subscribe to similar views in which consciousness, rather than the physical world, is seen as the ultimate reality.
From idealism it is only a short step to solipsism, the theory that the self is the only reality. Bertrand Russell tells the following story, " I once received a letter from an eminent logician, Mrs Christine Ladd Franklin, saying that she was a solipsist, and she was surprised that there were not others". (Bertram Russell quote from ‘Intellectual Impostors’ by Alan Sokal and Jean Bricmont)
We may be amused by Mrs Franklin's failure to realize that as a solipsist the existence of other solipsists was purely down to her. However, we might also sympathize with her, for the story points out how hard it is to sustain the view that the external world is not real. In moments of quiet reflection we may think that it is an illusion, but in daily life we continually experience it as a concrete reality. We have no apparent control over its laws, we must satisfy its needs and must act within its constraints. Illusion or not, we cannot walk through walls. Other people may be figments of our imagination, but they still retain the ability to uplift or harm us.
Given the fact that we cannot escape experiencing the physical world as it chooses, rather than as we choose, it appears that we are faced with two alternative positions: pragmatism and realism. The pragmatic approach is to accept the world as it appears through our senses, but without forming any fixed view as to whether it truly exists. We think of ourselves as being at the controls of a plane, with no way of knowing whether the aircraft is real or just a flight simulator. As pilots it makes no difference to what we need to do to fly it.
The alternative approach is realism, the doctrine that objects exist independently of sensory perception. A concern about realism is that it requires us to belief more than is strictly necessary to cope with the world. With pragmatism we are saying that we will accept the world as we experience it, with realism we are saying that the world is as we experience it, in the sense that it is made up of concrete objects.
Even if we accept that there is a real world, how reliable are our perceptions of it, and how accurate is the model of it that we create in our mind? For example, consider how two alternatively flashing lights are perceived. If the interval between the flashes is less than about 0.05 seconds, the lights will be seen as being permanently on. If the interval is slightly increased it will appear as if the light moves. If the interval is 0.15 seconds, then the sequential nature of the flashes is seen. This ties in with research which suggests that information is handled by the visual system in little packets, called frames. (You can imagine this as being like a movie film, where motion is represented as a series of images.) Everything that falls within a frame is treated as happening at the same instant.
Numerous other examples can be given to show that our senses provide only a partial and incomplete picture of the world.
Another issue about our knowledge of reality comes from the ideas put forward by the philosopher Immanuel Kant. He suggested that out minds have a form of intuition which provides the framework into which we fit sensory information. These intuitions include such things as the way we think about time, space and the laws of cause and effect.
For example, when we see a white billiard ball strike a red one, which then moves off in the direction of impact, we infer that red balls movement was caused by the white ball striking it. However, this idea of cause and effect did not arise through our senses, but rather was applied by the mind to the sensory information.
If Kant is right, then our perception of the world is formulated by concepts which come from our mind, rather than from the world outside us. Even if these concepts do in fact reflect reality, we are left with the interesting question as to whether there are aspects of reality we fail to comprehend, because our minds lack the necessary intuitions to do so.
Kant was one of the first philosophers to use the term 'phenomenon' . However, Phenomenology, the study of such phenomena is most closely associated with Edmund Husserl.
Husserl is the philosopher who pointed out that Descartes statement 'I think therefore I am', is not logically correct. The capability to think does not prove the existence of some unique 'I'. Husserl tried to establish a new kind of philosophy based on introspection, in which one would become acquainted with the 'pure objects of consciousness'. His concern was to explore the world of experience, as free as possible from conceptual presuppositions. Husserl himself believed that such studies required a previous suspension of belief in the reality of these phenomena (i.e. idealism). Husserl's project is seen to have failed, because he found no method of introspection that yielded consistent results. Today the importance of phenomenology lies in the realization that conscious experience is made up of a continual flow and flux of changing phenomena.
As for the he question, 'What exists?'. It remains unanswered and, from a philosophic point of view, unanswerable.
See also Truth.