Bellesa

The mathematician's patterns, like the painter's or the poet's, must be beautiful; the ideas, like the colours or the words, must fit together in a harmonious way. Beauty is the first test: there is no permanent place in the world for ugly mathematics... It may be very hard to define mathematical beauty, but that is just as true of beauty of any kind- we may not know quite what we mean by a beautiful poem, but that does not prevent us from recongnizing one when we read it.

                                                               G. H. Hardy