No doubt the past does not merely concern the history of error, as  
Schliesser argues. This applies to all sciences, even those which are not  
usually thought as historical ones. Just think of the recent discovery of  
what some claim is the 10th planet in the solar system. It is such a  
puzzling discovery that astronomers do not agree as to how to classify the  
object. Some argue that a planet should be roughly spherical and have a  
circular orbit around the sun, which is not the case here. Moreover, the new  
discovery brought back the debate about whether Pluto, which was discovered  
in 1930, should be called a planet. In this sense, this "anomaly" may  
precipitate a real revolution in contemporary Astronomy. Without a thorough  
understanding of the history of this field, the issues involved in the  
debate would not make sense.  
  
Ana Maria Bianchi