““ONE must sometimes believe what one cannot understand. That is the method of the scientist as well as the mystic: faced with a universe which must be endless and infinite, he accepts it, although he cannot really imagine it. For there is no picture in our minds of infinity; somewhere, at the furthermost limits of thought, we never fail to plot its end. Yet—if there is no end? Or if, at the end, we are only back at the beginning again?””