I said, in as simple terms as I can make it, that the real world is the one we directly perceive, and it is that world all our knowledge, the result of all our intellectual investigations in every field, is about. If there were no perceived world, there would be nothing to study, no science at all.
I suggest you re-read what I wrote if you didn't get it the first time ;)
You think that the purpose of reason is to explain concrete reality.
What qualifies as 'concrete reality'? My whole point was that WE DON'T KNOW IN ADVANCE OF THE PROCESS OF REASONING what concrete reality consists of. The very act of classifying something as 'concrete reality' is an act of reasoning. Our knowledge about all of concrete reality is always incomplete, since there are always new things we could discover.
The purpose of reasoning is not just to explain KNOWN reality, but to try to broaden our horizons by searching for NEW CONCRETES.
Therefore we can't make definite assumptions about what is and is not a part of 'concrete reality'.
How do you know that the computer you're seeing right now is concrete reality? You do not perceive that computer screen directly you know... the picture you¡¯re seeing is actually just electrical signals in your brain. As a child you REASONED that these electrical signals generated by light going into your eyes CORRESPOND to something outside your head and you RE-CLASSIFIED the mental pictures as representing part of 'concrete reality'. An extreme logical positivist would tell you that the computer doesn't exist, because all you are actually aware of is 'a picture of a computer in your head' and you shouldn't assume that the pictures correspond to anything in reality. That of course, is solipsism.
The truly rational person has to start by assuming that there is a concrete reality outside his head which is greater than the one he currently knows about. Then reason can be used to come up with models which CORRESPOND to as yet unknown concretes. If the reasoning is good, the person is entitled to conclude that their conceptions are not just 'abstract inventions for explaining known reality' but actually correspond to new things which have not yet been observed.
The rational person will then start to try to look for the proposed new things. If the new things exist a way will be found to directly observe them at some point and then the rational person can RE-CLASSIFY them as NEW CONCRETES. So what started off as an 'abstract device' got reclassified as a part of concrete reality later on.
Do you see how treating scientific concepts as mere 'abstract devices' actually hugely constricts us? A person who believes that the only concretes in reality are KNOWN concretes won't bother to search for anything new. You have to trust reason and believe in ¡®pictures in your head' to start with in order to have a chance of finding them in concrete reality!
To say that the purpose of reason is just to explain known concretes is comparable to a cave-man sitting watching shadows on his cave wall that refuses to turn his head to search for the source because he thinks that the shadows are all of reality.
(Edited by Marc Geddes on 8/12, 3:08am)