The very first illusion is to believe that there is one, unique world of perception. The mind and the world we experience are inseparable, as it is the mind that makes the world meaningful. Our mind IS our world. Despite the fact that our mental construct of what is perceived is distinct from the objective reality, our mind accepts it as real.
Every organism, man as well as animal, lives in its own subjective spatiotemporal world that semiotic philosophers call ‘Umwelt’ (from the German Umwelt, ‘surrounding world’, or ‘life-world’). According to the biologist Jakob J. von Uexküll, organisms and their life-world shape each other in a functional loop (see fig. below): interactions between the subject and the outer world, mediated through the sense and effect organs, determine the world framework of the subject. Thus, a particular stimulus which has a perceptive cue or meaning to the subject induces always a purposeful reaction.
The human being is a sponge who absorbs the changes of the physical world surrounding him. Actually, if the physical world had been unchanging, we wouldn’t need to receive sensations on the world that surrounds us since all would be static and everything would definitely have its final place!
Our sense organs continuously check, then, the changes of our immediate environment to allow us to act and react in keeping with it. If we see a wall in front of us, for example, we won’t charge into it, of course, but try to avoid it! Our senses however detect only a part of the reality – the most useful for us – and translate it in an ‘analogical’ way. Yes, our senses work analogically… For instance, it’s difficult to consider a single color in a distinct way, but always in relation to others. The same red color will be perceived differently according to the content or the context where it lies within.
Every living being has a ‘repertoire’ of sense organs which is peculiar to him, with a particular predilection for one or two sense organs: the human being favors sight; the dog, smell; for bats, it’s hearing… Concerning the color’s perception, animals do not all see in the same way because they aren’t perceptive to the same part of the luminous spectrum. Here are two extreme cases: insects, for example, see the ultraviolet rays, while on the other hand, some snakes can perceive infrared rays.