By Jonathan Awesome
It is said that the sense can distort reality. The senses do nothing but react to stimuli, they are not capable of error. They are causal mechanisms which allow you to know reality by their interactions with parts of it. Misinterpretation of what your sense tell you is possible, but the only way to resolve or discover such errors in interpretation is by collecting more perceptual data. That we can reason is what makes us capable of mistakes but it also makes us capable of an enormous amount of knowledge. The sense are not flawed but the proper method of reasoning must be employed in interpreting what they give us.
The fact of qualia has been brought up to suggest that the mind may work differently for different people and that this may cause them to reach different conclusions. We all have the same basic mechanism of consciousness, the same kind of brain, so we should all have nearly the same form of consciousness. As an illustration of this; all of a given make of car have the same basic mechanisms of energy production and use, thus they all perform in the same ways. Nearly identical physical natures result in nearly identical processes. We can’t know exactly what it is like to be conscious for someone else because we cannot experience awareness through them introspectively. But we do know that the mechanisms involved are the same and can draw the conclusion that the processes are the same extrospectively.
Now, there are two meaning of the word rational. In one sense it means that we are capable of reason. This we know introspectively by doing such things as considering this issue. This is the sense in which humans (leaving aside those with brain damage, etc) are all rational. The second meaning is the more common: to be rational is to employ reason properly, actively and consistently. To employ reason properly means to do it in such a way as to reflect reality in our conclusions.
Because the senses give us the nature of reality (through interacting with it) and because they are our only direct connection to reality they must be our starting point in reasoning if we are to be rational. This much is clearly possible to us, to think beginning with our perception, what we can observe. We can be objective and objectivity is a requirement of rationality. But we must also avoid errors in thinking because clearly errors are possible in reasoning as honest people do sometimes reach different conclusions. This is what logic is for.
Logic is a method of reasoning that insures (when properly employed) that what we conclude is consistent with what we began with in reasoning. We can observe in all things that they have particular characteristics, they are certain things and can act only in certain ways. We can induce that to be something, to exist, is to be something specific and limited; to have a characteristic is to have that characteristic and no other that is incompatible with it at the same time and in the same respect. We can know that there can be no all red birds that are at the same time all blue in the same way. We can induce that contradictions do not exist, the laws of identity and non-contradiction. So we know that to commit a contradiction in reasoning means to be mistaken. From this we develop the whole of logic as a method. And because we can employ logic and perceive reality we can be rational if we so choose.
Knowledge is the position of an idea that reflects reality. It has been suggested that knowledge is impossible because people can be certain of contradicting ideas. But certainty can be mistakenly obtained by means other than objectivity and proper reasoning. So a disagreement doesn’t mean that no one can know the answer, only that someone has not employed or employed properly objectivity or reason and that his ideas do not then reflect reality. One (or more) of those who disagree are simply wrong. Knowledge is possible.