I was thinking quite lot about it, and unfortunately I don't understand so maybe someone could help me. If we perceive, for instance a car in front of us and see that it's made of parts, how can we know of what smaller parts is it made? I mean if we see that the car is red, is it possible that the car has some very small parts that are, for example, orange, but it appears to us that the whole car is red because those smaller parts aren't big enough for our eye to perceive it. One thing that really intrigues me about this is that if we see two objects that are the same to our eyes, and on the molecular level they are different, how can we really conclude that those objects posses the same properties when in fact theay are different on a certain level. Is their outside that is 'available' to our eyes the same on both objects, or does the 'redness' subsume even the 'orangeness' on the smaller level. I hope you understand me because relating this to the 'sum of parts' and going from a higher to a lower level of things really confuses me.
Equating the sum of parts to an automobile and parts of the engine, transmission or within the dash which are usually not given to us perceptually as the vehicle moves along a highway might be better served with examples from chemistry.
Chemically speaking water is comprised of hydrogen and oxygen. Water can quench thirst, extinguish some fires, drown a person, yet of the parts, hydrogen can explode or burn in the presense of oxygen with the addition of a spark. Oxygen is required for breathing, and is the element required for combustion of all combustable materials.
Salt would be another example that adds savor to foods. It's parts, sodium and chloride are both caustic to human life.
On the perceptual level, we cannot perceive that water or salt are comprised of the chemical elements involved. To arrive at them as the sum of their parts, we had to discover that there were mixtures and compounds. Various experiments were conducted that permitted us to discover that some things could be broken into different elements via adding different compounds which combined with one or more elements in a compound leaving another, applying electrolysis to a compound which resulted in two or more different elements. Further examination allowed us to discover that each element and compound had differing properties such as melting and boiling points, hardness, specific reactions to other elements introduced. Chains of procedures and a variety of different tests gave rise to understanding of what water, salt, sugar, etc, were comprised of.
Starting with the identification of water, we learned that it had causal properties of quenching thirst and extinguishing some fires. Later, by heating mercury oxide in a closed flask, it was discovered that it resulted in the liquid mercury metal and a gas that promoted combustion. Hydrogen was discovered as a gas liberated by iron, zinc, or tin when exposed to various acids. When these two gases were ignited within a closed chamber, the resultant “dew” encountered was identified as water. Perceiving things as the sum of parts is an ongoing process of identification, knowledge gained by applying reason to perception in conjunction with controlled experimentation to wrest new knowledge from existence by the continued application of applying reasoning to perception.
answered Oct 18 '12 at 23:33