FALLACIES OF OBSERVATION. 393 



that the simplest experiment would have shown to be 

 erroneous, continued to be entertained because nobody 

 ever thought of trying that experiment. One of the 

 most remarkable of these was exhibited in the Coper- 

 nican controversy. The opponents of Copernicus 

 argued that the earth did not move, because if it did, 

 a stone let fall from the top of a high tower would not 

 reach the ground at the foot of the tower, but at a 

 little distance from it, in a contrary direction to the 

 earth's course: in the same manner (said they) as, if a 

 ball is let drop from the mast-head while the ship is 

 in full sail, it does not fall exactly at the foot of the 

 mast, but nearer to the stern of the vessel. The 

 Copernicans would have silenced these objectors at 

 once if they had tried dropping a ball from the mast- 

 head, because they would have found that it does fall 

 exactly at the foot, as the theory requires: but no; 

 they admitted the spurious fact, and struggled vainly 

 to make out a difference between the two cases. " The 

 ball was no part of the ship and the motion forward 

 was not natural, either to the ship or to the ball. The 

 stone, on the other hand, let fall from the top of the 

 tower, was a part of the earth; and therefore, the 

 diurnal and annual revolutions which were natural to 

 the earth, were also natural to the stone; the stone 

 would, therefore, retain the same motion with the 

 tower, and strike the ground precisely at the bottom 

 of it*." 



Other examples, scarcely less striking, are recorded 

 by Mr. Whewellf, where imaginary laws of nature 

 have continued to be received as real, merely because 

 no one person had steadily looked at facts which 



* PLAYFAIR'S Dissertation, sect. 4. 

 t W HE WELL'S Phil, of the Inductive Sciences, ii., 203. 



