"The combinations that can be formed with numbers and symbols are an infinite multitude. In this thicket how shall we choose those that are worthy of our attention? Shall we be guided only by whimsy... [This] would undoubtedly carry us far from each other and we would rapidly cease to understand each other. But that is only the minor side of the problem. Not only will physics perhaps prevent us from getting lost but it will also protect us from a more fearsome danger... turning around forever in circles. History [shows that] physics has not only forced us to choose [from the multitude of problems which arise, but it has also imposed on us directions that would never have been dreamed of otherwise What could be more useful"
H. Poincare

"A man's mind grows narrow in a narrow place, whose mind is enlarged only because he has lived in a large place: but what is got by books and thinking is preserved in a narrow place as well as in a large place. A man cannot know modes of life as well in [Princeton] as in London; but he may study mathematicks as well in [Princeton]."
Samuel Johnson

"...I had the occasion to ask him [Henry Moore] how one should view sculptures: from afar or from near by. Moore's response was that the greatest sculptures can be viewed -- indeed, should be viewed -- from all distances since new aspects of beauty will be revealed in every scale. Moore cited the sculptures of Michelangelo as examples: from the excellence of their entire proportion to the graceful delicacy of the fingernails. The mathematical perfectness of the black holes of Nature is, similarily, revealed at every level by some strangeness in the proportion in conformity of the parts to one another and to the whole."- Subrahmanyan Chandrasekhar

Relativity, explained!