This is my response to caveblogem‘s third post on Radical Contructivism. For convenience of reference I reproduce the postulate from that post but readers would be advised to read the post for themselves (by clicking on the above link) as well as the rather interesting comments added to it.
Postulate Number I (revised)–The process by which we acquire knowledge is limited, hobbled, and distorted by a number of things.
The idea that we are somehow prevented from knowing the world “as it really is” because we have to receive information about it through an imperfectly functioning nervous system and process these “data” with an imperfectly functioning brain strikes me as paradoxical. It reminds me of evangelists who postulate that we are in a state of mortal sin so that they can sell us the salvific remedy. If you reject the proposition, the need for a remedy disappears.
I have difficulty understanding what this “world as it really is” is supposed to be. If I am incapable of knowing it, how do I know it exists? In order to say that View A of the world is inferior to View B, which is the world “as it really is”, we surely have to produce View B for all to see and to compare Views A and B. If View B is unobtainable then by what right do we dismiss View A as inferior to it?
In case you think this is mere hair-splitting, let me state it again succinctly: in order to evaluate our view of the world as good or bad, true or false, we need a measure against which to evaluate it. The only measure that the Radical Constructivists seem to offer us is “the world as it really is” which they assert is inaccessible to us. That being so, no evaluation is possible. It’s a null match.
I know what the problems are supposed to be. Inter alia, they are set out in Bertrand Russell’s The Problems of Philosophy. My short summary goes like this:
Look at a table: what do you see? You see a rectangle – or is it a trapezium or is it a rhombus? – that changes shape as you approach, retreat and move around the table. It is brown – or is it? It has a white patch on it where light from the window is reflected from it to your eyes. The white patch changes place, shape and colour as you approach, retreat and move round the table. (And so on and so on.) This being so, that the table changes its appearance at every instant, how can we say that we really are seeing the table “as it really is”?
I think our first response must surely be to ask “What do you mean by ‘the table as it really is’?” Why do you think there is something else; can you show me this something else? If not, why do you assert that there is a something else? You claim that my knowledge of the table is at best indirect but I can at least point to data coming from that table whereas you do not even have indirect evidence for this putative alternative “world as it really is”. You are merely postulating it.
Yes, tables change their appearance according to how we look at them and the eye is subject to optical illusions. Percival Lowell did see “canals” on Mars where better pictures show dots and patches but what does this prove? The “real world” does not stop at the surface of the eye. It continues through the eye, up the optic nerve, into the brain. The “canals” that Lowell saw were part of the real world.* They were the dots and patches on the surface of Mars as “imaged” by the low-resolution human eye. A camera attached to a low powered telescope will produce a similar result. A more powerful telescope will “resolve” the dots and patches and show them as such. We know all this: it is familiar ground for a scientist.
Science describes the world. It describes it in human terms but what other terms are there? Do we know that there are any other terms? Doing science is like doing a jig-saw puzzle: you fit the pieces together to form a picture. The difference is that as science proceeds, the pieces change; we acquire more of them and the resolution improves. Therefore the picture we are building improves. We are building a picture, not a world. No one says that the world resides inside a physics textbook. The world is all around us, we are part of it and we are learning about it, building pictures of it to help us understand it.
In sum, I agree that “The process by which we acquire knowledge is limited” but I don’t agree that it is “hobbled, and distorted”.
“Hobbled” implies that the mind is not being allowed to operate to the limit of its capacity but is being held back by something. By what? The mind is the mind and it works as it works. No one is putting shackles on it. Any limitations are inbuilt and science is in the business of stretching its capabilities to the full.
“Distorted” implies that we have an undistorted view with which to compare it and see that it is distorted but this is precisely what the Radical Constructivists deny that we have.
*I have every regard for Lowell but think that on this occasion he let his imagination run away with him. As a scientist he should have suspended judgement until he had sufficient evidence.