“Poincaré made the following statement of the principle of relativity: ‘According to the principle of relativity, the laws of physical phenomena must be the same for a fixed observer as for an observer who has a uniform motion of translation relative to him, so that we have not, nor can we possibly have, any means of discerning whether or not we are carried along in such a motion.’ When this idea descended upon the world, it caused a great stir among philosophers, particularly the ‘cocktail-party philosophers,’ who say, ‘Oh, it is very simple: Einstein’s theory says all is relative!’ In fact, a surprisingly large number of philosophers, not only those found at cocktail parties (but rather than embarrass them, we shall just call them ‘cocktail-party philosophers’), will say, ‘That all is relative is a consequence of Einstein, and it has profound influences on our ideas.’ In addition, they say ‘It has been demonstrated in physics that phenomena depend upon your frame of reference.’ We hear that a great deal, but it is difficult to find out what it means. Probably the frames of reference that were originally referred to were the coordinate systems which we use in the analysis of the theory of relativity. So the fact that ‘things depend upon your frame of reference’ is supposed to have had a profound effect on modern thought. One might well wonder why, because, after all, that things depend upon one’s point of view is so simple an idea that it certainly cannot have been necessary to go to all the trouble of the physical relativity theory in order to discover it. That what one sees depends upon his frame of reference is certainly known to anybody who walks around, because he sees an approaching pedestrian first from the front and then from the back; there is nothing deeper in most of the philosophy which is said to have come from the theory of relativity than the remark that ‘A person looks different from the front than from the back.’ The old story about the elephant that several blind men describe in different ways is another example, perhaps, of the theory of relativity from the philosopher’s point of view. But certainly there must be deeper things in the theory of relativity than just this simple remark that ‘A person looks different from the front than from the back.’ Of course relativity is deeper than this, because we can make definite predictions with it. It certainly would be rather remarkable if we could predict the behavior of nature from such a simple observation alone.” – Richard P. Feynman, The Feynman Lectures on Physics, Vol. I (emphasis in original)