142 GALILEO AND HIS JUDGES. 



Sun, that the Earth, occupying the position it does, 

 should be at rest, while the Sun, controlling the 

 motions of the planets (vast bodies, some of them), 

 circled, nevertheless, round the Earth ; the improba- 

 bility, I say, of this is so great as to be almost 

 overwhelming ; at any rate, unless the difficulties 

 of the counter hypothesis were shown to be insur- 

 mountable, which, as we know, is far from being the 

 case. It was of course possible, without going the 

 lengths of the Paduan professor, and setting oneself 

 against the telescope altogether, to admit the facts 

 but deny the inferences ; to grant, for instance, that 

 Mars appeared to have a diameter more than six 

 times as great in one position as in another, and 

 to attribute it, as I hinted just now, to some extra- 

 ordinary eccentricity in his orbit round the Earth ; 

 but it is not wise to look through a telescope with 

 the eyes of the body open and the eyes of the 

 mind closed ; and generally it is but right to be 

 guided by clear and distinct probabilities when 

 discussing questions of natural philosophy on scientific 

 grounds and it is of these alone that I am at 

 the present moment speaking. 



It must be borne in mind distinctly that the 

 discovery of the moon-like phases of Venus, showing 

 her to revolve round the Sun, was simply conclusive 

 as against the old system of Ptolemy, which had 

 so long been the received system of astronomy. The 

 theory of Tycho Brahe, or some modification of it, 

 was the only one that could henceforth be adopted. 



