Why are senses so important to the human body? All our knowledge has its origins in perceptions; to the ancient Greeks, sensitivity constituted the essential difference between plants and animals and between animals and humans. It was not that any specific sense was better developed in humans; just one glance at the animal kingdom will give examples of more acute vision (birds of prey), hearing (dogs and bats), or smell (insects).
Rather, between them, they provided a range of information that the intelligent brain could sift through and use to communicate, socialize, improvise, and invent. Every moment of our waking lives, millions of sensory signals from the eyes, nose, mouth, ears, and skins are sent to the brain, most of which are never perceived on a conscious level.
The brain continuously modifies, examines, filters out, and even completes all of these impulses. It is for example, hard to find the blind spot in the eye not because it is not there but because the brain fills in the missing part of the visual jigsaw. The world of perception is very different from and much more selective than the world of sensation.
Moreover, in adulthood, the senses have a strict hierarchy, ruled first by the eyes and then by the ears, the distance senses of sight and hearing, and only later by the skin, the mouth, and the nose, the proximity senses of touch, taste, and small. You can see how this sensual hierarchy organizes itself simply by closing your eyes. What happens?
Your subjective inner world becomes filled with sound. You can pick up the rhythm of your own breathing and background noise, which you may not have been aware of before, seems amplified. You do not need absolute quiet like before; it seems amplified. You do not need absolute quiet to hear a pin drop when your eyes are shut. If you carry this experiment one stage further and place your hands over your ears, you will now find that sensation comes predominantly from your sense of touch.
You will suddenly become aware of the comparative softness or hardness of the chair on which you are sitting, of the texture of the clothes you are wearing, and of sensations arriving from different parts of your body, including your neck, your back, your shoulders, and even your scalp. These are not new sensations; they are continually communicated to the brain via the skin. The difference is that you have only just begun to perceive them.
Further, we are all much more receptive to the messages arriving from our senses than we perhaps realize, although most of the time we make use of just a fraction of their full potential. Consider the skill of the piano tuner, who can detect and correct even the smallest pitch fluctuation because he knows every note in the scale by memory.
The discernment of the master of wine, who has educated his senses of smell and taste to such a point of refinement that he can identify not only the vintage of a certain wine but the locality and even the vineyard that produced it.
