The mathematical facts worthy of being studied are those which, by their analogy with other facts, are capable of leading us to the knowledge of a physical law. – Henri Poincare
Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house. – Henri Poincare
The scientist does not study nature because it is useful he studies it because he delights in it, and he delights in it because it is beautiful. – Henri Poincare
One would have to have completely forgotten the history of science so as to not remember that the desire to know nature has had the most constant and the happiest influence on the development of mathematics. – Henri Poincare