XXVI. Of the Intellectual Powers according to Plato. 

 By the Rev. W. Whewell, D.D. Master of Trinity College. 



[Read November 12, 1855.] 



In the Seventh Book of Plato's Republic, we have certain sciences described as the instruments 

 of a philosophical and intellectual education ; and we have a certain other intellectual employ- 

 ment spoken of, namely, Dialectic, as the means of carrying the mind beyond these sciences, 

 and of enabling it to see the sources of those truths which the sciences assume as their first 

 principles. These points have been discussed in the two preceding papers. But this scheme of 

 the highest kind of philosophical education proceeds upon a certain view of the nature and degrees 

 of knowledge, and of the powers by which we know ; which view had been presented in a great 

 measure in the Sixth Book ; this view I shall now attempt to illustrate. 



To analyse the knowing powers of man is a task so difficult, that we need not be surprized 

 if there is much obscurity in this portion of Plato's writings. But as a reason for examining 

 what he has said, we must recollect that if there be in it anything on this subject which was 

 true then, it is true still ; and also, that if we know any truth on that subject now, we shall 

 find something corresponding to that truth in the best speculations of sagacious ancient writers, 

 like Plato. It may therefore be worth while to discuss the Platonic doctrines on this matter, 

 and to inquire how they are to be expressed in modern phraseology. 



Plato's doctrine will perhaps be most clearly understood, if we begin by considering the 

 diagram by which he illustrates the different degrees of knowledge*. He sets out from the dis- 

 tinction of visible and intelligible things. There are visible objects, squares and triangles, for 

 instance ; but these are not the squares and triangles about which the geometer reasons. The 

 exactness of his reasoning does not depend on the exactness of his diagrams. He reasons from 

 certain mental squares and triangles, as he conceives and understands them. "Thus there are 

 visible and there are intelligible things. There is a visible and an intelligible world + : and there 

 are two different regions about which our knowledge is concerned. Now take a line divided into 

 two unequal segments to represent these two regions : and again, divide each segment in the 

 same ratio. The parts of each segment are to represent differences of clearness and distinct- 

 ness, and in the visible world these parts are things and images. By images I mean shadows, 



Pol. vi. § 19. | has any connexion with ouranon, heaven, that I may not be 



t He adds, " This oratnn, this visible world, I will not say I accused of playing upon words." 



