When we read a speedometer, Barfield reminds, it is well to remember that we are not actually experiencing the speed of the car. Similarly, when we inspect the findings of a radio-telescope, we must remind ourselves that we have only dashboard-knowledge of the nature of the stars.1
When we look at modern science's conception of theory and hypothesis, and its acceptance of the "if it works it must be true" approach, it "is almost as if they expected dashboard-knowledge to tell us how the engine was made" (SA 60). Galileo may have counseled--as one of the foundational principles of the scientific revolution--that "In every hypothesis of reason, error may lurk unnoticed, but a discovery of sense cannot be at odds with the truth" (quoted in WA 26), but in fact much of modern science now has little to do with "discoveries of sense," relying wholly on dashboard knowledge instead.
It was in Poetic
Diction that Barfield first introduces the concept of dashboard knowledge
in a striking parable:
Once upon a time there was a very large motor-car called the Universe. Although there was nobody who wasn't on board, nobody knew how it worked or how to work it, and in the course of time two very different problems occupied the attention of two different groups of passengers. The first group became interested in invisibles like internal combustion but the second group said the thing to do was to push and pull levers and find out by trial and error what happened. The words "internal combustion," they said were obviously meaningless, because nobody ever pushed or pulled either of these things. For a time both groups agreed that knowledge of how it worked and knowledge of how to work it were closely connected with one another, but in the end the second group began to maintain that the first kind of knowledge was an illusion based on a misunderstanding of language. Pushing, pulling, and seeing what happens, they said, are not a means to knowledge; they are knowledge. It was an odd sort of car, because, after the second group had with conspicuous success tried pushing and pulling all the big levers, they began on some of the smaller ones, and the car was so constructed that nearly all of these, whatever other effect they had, acted as accelerators. Meanwhile the first group held its breath and began to think that their kind of knowledge might perhaps come in useful after the smash. (PD 23-24)He returned to the analogy in later books. In Saving the Appearances, for example, we find the following:
Burgeon: . . . To my mind the very word "radio-telescope"-- and "radio-microscope," too, for that matter--is a hidden lie. A telescope is an instrument for seeing things at a distance. If I understand rightly, you don't see anything at all through a radio--telescope except a lot of squiggles on a screen.
Burgeon: Exactly! You might as well say a man who is looking at a speedometer--no, at a column of figures made up from speedometer-readings, is seeing the speed of the car!
Ranger: Well, isn't he?
Burgeon: He's not looking at it anyway. He's looking at a pointer that measures it. (WA 18)