204 ERRORS ATTRIBUTED TO ARISTOTLE. 



careful to refer to their observations, and to explain why, 

 in his judgment, they fell into the errors which he 

 corrects. 



Aristotle's knowledge, in fact, appears to have stood 

 in the same relation to that of such men as Polybus and 

 Diogenes of Apollonia, as that of Herophilus and Era- 

 sistratus did to his own, so far as the heart is concerned. 

 He carried science a step beyond the point at which he 

 found it ; a meritorious, but not a miraculous, achieve- 

 ment. What he did, required the possession of very 

 good powers of observation ; if they had been powers 

 of the highest class, he could hardly have left such con- 

 spicuous objects as the valves of the heart to be discov- 

 ered by his successors. 



And this leads me to make a final remark upon a 

 singular feature of the " Historia Animalium." As a 

 whole, it is a most notable production, full of accurate 

 information, and of extremely acute generalisations of 

 the observations accumulated by naturalists up to that 

 time. And yet, every here and there, one stumbles 

 upon assertions respecting matters which lie within the 

 scope of the commonest inspection, which are not so 

 much to be called errors, as stupidities. What is to be 

 made of the statement that the sutures of women's skulls 

 are different from those of men ; that men and sundry 

 male animals have more teeth than their respective fe- 

 males ; that the back of the skull is empty ; and so on ? 

 It is simply incredible to me, that the Aristotle who 

 wrote the account of the heart, also committed himself 



