All this is just an analogy. - Robert M. Pirsig

Your common sense is nothing more than the voices of thousands and thousands of these ghosts from the past.

"The result is rather typical of modern technology, an overall dullness of appearance so depressing that it must be overlaid with a veneer of "style" to make it acceptable. And that, to anyone who is sensitive to romantic Quality, just makes it all the worse. Now it's not just depressingly dull, it's also phony. Put the two together and you get a pretty accurate basic description of modern American technology: stylized cars and stylized outboard motors and stylized typewriters and stylized clothes. Stylized refrigerators filled with stylized food in stylized kitchens in stylized homes. Plastic stylized toys for stylized children, who at Christmas and birthdays are in style with their stylish parents. You have to be awfully stylish yourself not to get sick of it once in a while. It's the style that gets you; technological ugliness syruped over with romantic phoniness in an effort to produce beauty and profit by people who, though stylish, don't know where to start because no one has ever told them there's such a thing as Quality in this world and it's real, not style. Quality isn't something you lay on top of subjects and objects like tinsel on a Christmas tree. Real Quality must be the source of the subjects and objects, the cone from which the tree must start."

If I hold my head to the left and look down at the handle grips and front wheel and map carrier and gas tank I get one pattern of sense data. If I move my head to the right I get another slightly different pattern of sense data. The two views are different. The angles of the planes and curves of the metal are different. The sunlight strikes them differently. If there's no logical basis for substance then there's no logical basis for concluding that what's produced these two views is the same motorcycle.