A philosophical idea that I find fun to play with is that what we perceive is not what actually happens in reality. For example, when I hear music being played, I perceive a beautiful chord or a groovy beat. What is physically happening is that the air is vibrating in waves that align harmoniously and have a rhythmical pattern.
The vibrations in the air, which is what is actually happening in the physical world, is not something that is inherently part of my experience of sound. If the vibrations are strong enough to be felt, they are perceived by my sense of touch.
Even after the vibration in the air reaches my ears, my nervous system translates them into electrical impulses, and that is what reaches the brain. So the vibrations in the air are translated into electricity, and then those electrical impulses are translated again into the experience of sound.
When science revealed how our physiology interprets external events into our sense perceptions, to the extent that they do not resemble the external phenomenon at all, the question arose of how connected our perceptions are to reality. Some philosophers questioned whether we can know reality at all. There is a vast spectrum of thoughts on the subject.
Despite there being so many clever opinions on the subject already, I am going to share mine. First of all, it seems sensible to accept the best scientific knowledge we have of ourselves at this time and acknowledge that are sense perceptions are interpretations of the outside world, and not a direct experience of it.
I like using the word interpretation here, because it seems to me that my sense perceptions are the impression the outside world makes on me. When I press down on a key to type a letter, I experience the impression the keyboard makes on me according to my physiology, sense being stimulated, and general organization as a human being.
The idea that my perceptions are dependent on my physiology helps reconcile how the same thing, such as light, can be perceived in wildly different ways. If light reaches my eye, I have the experience of color. If light reaches my skin, I have the experience of warmth. Sometimes I even have the experience of pain, but always in accordance with how my different senses interpret the world.
Given that my senses only provide me with wildly different interpretations of the world, how can I gain access to the reality they hint at? For starters, there are a variety of unconscious processes that make my senses seem coherent and connect all of the different information from sight, hearing, touch, and the rest of my senses. Thus, when I am typing on the keyboard and bother to look at it, I connect both perceptions as applying to the same thing.
I may not have direct access to the reality behind my perceptions, but I do have access to the interpretations my senses provide of that reality. In other words, I have access to the (interpreted) impression the world makes on me through my senses. These impressions are clues left by reality through its affect on me, and through thinking I can relate to, understand, and form a concept for what caused my sense impressions.
The process of arriving at an idea of reality through thinking about the clues in my perceptions is like being a detective for me. I as the detective may never have seen the perpetrator of a crime. However through the impression they leave, and the way the environment has responded to their presence according to its features, I can arrive at a true and accurate concept and description of my suspect through thinking about the clues.
Arriving at a concept of reality through thinking about my perceptions happens the same way for me, with one interesting difference. Because I am the one perceiving and thinking, I am both the scene of the crime in that the passing of something real leaves behind clues in my various senses, each according to their nature, and I am the detective who thinks about them.
The Thoughtful Thought 