As a result of the physical facts described so far, we may conclude the
following. Everything we perceive as the "matter", "world" or
"universe" is nothing but electrical signals occurring in our brain.
Someone eating a fruit in fact confronts not the actual fruit but its
perception in the brain. The object considered to be a "fruit" by the person
actually consists of an electrical impression in the brain concerning the shape, taste,
smell, and texture of the fruit. If the sight nerve travelling to the brain were to be
severed suddenly, the image of the fruit would suddenly disappear. Or a disconnection in
the nerve travelling from the sensors in the nose to the brain would completely interrupt
the sense of smell. Simply put, the fruit is nothing but the interpretation of electrical
signals by the brain.
Bundles of light coming from an object fall on the retina
upside-down. Here, the image is converted into electrical signals and transmitted to the
centre of vision at the back of the brain. Since the brain is insulated from light, it is
impossible for light to reach the centre of vision. This means that we view a vast world
of light and depth in a tiny spot that is insulated from light.
Another point to be considered is the sense of distance. Distance,
which is to say the distance between you and this book, is only a feeling of emptiness
formed in your brain. Objects that seem to be distant in that persons view also
exist in the brain. For instance, someone who watches the stars in the sky assumes that
they are millions of light-years away from him. Yet what he "sees" are really
the stars inside himself, in his centre of vision. While you read these lines, you are, in
truth, not inside the room you assume you are in; on the contrary, the room is inside you.
Your seeing your body makes you think that you are inside it. However, you must remember
that your body, too, is an image formed inside your brain.
The "external world" presented to us by our perceptions is
merely a collection of the electrical signals reaching our brain. Throughout our lives,
these signals are processed by our brain and we live without recognising that we are
mistaken in assuming that these are the original versions of matter existing in the
"external world". We are misled because we can never reach the matter itself by
means of our senses.
Moreover it is again our brain that interprets and attributes meaning
to the signals that we assume to be the "external world". For example, let us
consider the sense of hearing. It is in fact our brain that transforms the sound waves in
the "external world" into a symphony. That is to say, music is also a perception
created by our brain. In the same manner, when we see colours, what reaches our eyes are
merely electrical signals of different wavelengths. It is again our brain that transforms
these signals into colours. There are no colours in the "external world".
Neither is the apple red nor is the sky blue nor the trees green. They are as they are
just because we perceive them to be so. The "external world" depends entirely on
Even a slightest defect in the retina of the eye causes colour
blindness. Some people perceive blue as green, some red as blue, and some all colours as
different tones of grey. At this point, it does not matter whether the object outside is
coloured or not. In conclusion, the reason we see objects coloured is not because they are
coloured or because they have an independent material existence outside ourselves. The
truth of the matter is rather that all the qualities we ascribe to objects are inside us
and not in the "external world".
So what remains of the "external world"?