We spend our live forming new neural connections, making new chains of RNA molecules that constitute the chemical basis of our memories, and creating a framework of belief. Reality is perceived by each human being in a different way. Its perception is shaped by previous experiences, emotions, and cognitive facilities. According to the dictionary, objectivity has many meanings: being free from personal feelings or prejudiced, being unbiased, being intent upon things external from the mind and of or pertaining to what is known and composed of or relating to things that occupy space and can be perceived by the senses. But the dictionary fails to take into account that the senses themselves are already biased in some way.

Knowing that our world is not fixed, nor our Truths known, objectivity is outside the realms of humanity, since we are shaped by the way that we interact with the world. According to Einstein the only measurements which are ever truly objective are those made by machines, since they are calibrated to take only a particular reading. When we take these readings into the nervous system, there is already a degree of subjectivity. The sensory interface has a predetermined range of experiences that have developed over eons to best accommodate our environment. The eye is attuned to perceive edges, to decipher a world of contrasts, the nose and taste receptors have a very particular range which is narrower than many other mammals, and our range of touch is not quite as broad nor sensitive as other creatures. Thus since we are constrained by the boundaries of our body we cannot know nor sense everything in reality. Our knowledge being incomplete - objectivity remains some unattainable ideal.

We live in a circular loop, whereby we act upon reality and it in turn changes us. The model that we have of reality is one that we agree upon within ourselves. We can share our personal interpretations, the output of each individual mind, but it will always remain individual and subjective. The search for the closest approximation of objective reality is an integral part of striving to further clarify and draw away from ignorance the principles whereby we govern our lives

Relativism is the idea that the world, our reality, is in constant flux.> This principle applies directly to the way the nervous system interacts with the world. Our perception of the world is constantly changing. We have within us billions of different neural pathways and the probability of any particular path being chosen is completely indeterminate. The particular combination of excitatory and inhibitory stimuli that will arrive at any particular moment will determine which pathway is taken. It is the way that the nervous system conveys the information to the cortices in the brain that is the first step in translating an objective world into the subjective world within us.

Thus we see a world built of the nervous system's imagination. Because of the way we sense the world, there are particular concepts or ideas that we can guess at, and feel their secondary effects, but never truly experience - eg: our present model of the atom. We believe that it is circumnavigated constantly by an electron because such a model best fits the interpretation of the results we have found. But, we have never truly been able to measure the position, nor the speed of this particle at the same time. An uncertainty principle, which is the foundation of how we perceive reality. Since we have a narrow range, and in some places blind spots, we can never truly be sure of what is actually our there, or what we are filling in.

LOTS of interesting thoughts (be careful, though, about RNA as the repository of memories; it ain't (of course) that simple). Yes, we affect things outside of us, which in turn affect us. And yes, our inputs are limited (at any given time). Most interestingly, it all does raise an interesting question about the meaning of "objective", a term which is of course also a product of the brain, and hence subject to change. Maybe it isn't the "world" which is "objective" (a poor definition, since we can't, as you point out, ever completely see that), but rather a process of the brain which constitutes "objectivity"? How about the possibility that "objective" means what is similar in the potentially very different understandings of "reality" that different people have? Or, maybe even better, "objective" is the process of trying to specify and make use of those experiences which are common to everybody (or at least lots of people)? PG