PREFACE 



Among the rare books in the hbrary where I am 

 writmg there is a first edition of Gahleo's treatise 

 Dialogo sopra i due massimi sistemi del mondo, Tolemaico 

 e Copernicano. This was the work that brought him 

 before the Roman Inquisition. By the Holy Office he 

 was convicted ''of beheving and holding the doctrines — 

 false and contrary to the Holy and Divine Scriptures — 

 that the Sun is the centre of the world, and that it does 

 not move from east to west, and that the Earth does 

 move and is not the centre of the w^orld; also that an 

 opinion can be held and supported as probable after 

 it has been declared and decreed contrarj^ to the Holy 

 Scriptures," and he was required by the Holy Office to 

 "abjure, curse, and detest the aforesaid errors." 



Intolerance of unwonted views was not limited to the 

 Holy Office. Galileo himself could close the windows 

 of his mind and vent his critical scorn upon an adven- 

 turous colleague. In the fourth chapter of his fatal 

 book there is a discussion of the theory of terrestrial 

 tides which was the occasion of Galileo's treating with 

 disdain the suggestion of Kepler that the tides are 

 dependent upon the attraction of the Moon. To 

 Galileo this seemed an explanation by an appeal to 

 "occult Qualities and to such like vain Imaginations, 

 that are so far from being, or being possible to be 

 Causes of the Tide that on the contrary, the Tide is the 

 cause of them, that is, of bringing them into the brains 



