INDISTINCTNESS OF IDEAS. 193 



are themselves men of indistinct views, for they could not otherwise 

 avoid assenting to the demonstrated truths of science ; and, so far as 

 they may be taken as specimens of their contemporaries, they prove 

 that indistinct ideas prevail in the age in which they appear. In the 

 stationary period, moreover, the indefinite speculations and unprofit- 

 able subtleties of the schools might further impel a man of bold and 

 acute mind to this universal skepticism, because they offered nothing 

 which could fix or satisfy him. And thus the skeptical spirit may 

 deserve our notice as indicative of the defects of a system of doctrine 

 too feeble in demonstration to control such resistance. 



The most remarkable of these philosophical skeptics is Sextus 

 Empiricus ; so called, from his belonging to that medical sect which 

 was termed the empirical, in contradistinction to the rational and 

 methodical sects. His works contain a series of treatises, directed 

 against all the divisions of the science of his time. He has chapters 

 against the Geometers, against the Arithmeticians, against the Astrol- 

 >, against the Musicians, as well as against Grammarians, Rhet- 

 oricians, and Logicians; and, in short, as a modern writer has said, his 

 skepticism is employed as a sort of frame-work which embraces an 

 encyclopedical view of human knowledge. It must be stated, how- 

 ever, that his objections are rather to the metaphysical grounds, than 

 to the details of the sciences ; lie rather denies the possibility of spec- 

 ulative truth iu general, than the experimental truths which had been 

 then obtained. Thus his objections to geometry and arithmetic are 

 founded on abstract cavils concerning the nature of points, letters, 

 unities, &c. And when he comes to speak against astrology, he says, 

 "I am not going to consider that perfect science which rests upon 

 geometry and arithmetic ; for I have already shown the weakness of 

 those sciences : nor that faculty of prediction (of the motions of the 

 heavens) which belongs to the pupils of Eudoxus, and Hipparchus, and 

 the rest, which some call Astronomy ; for that is an observation of 

 phenomena, like agriculture or navigation : but against the Art of 

 Prediction from the time of birth, which the Chaldeans exercise." 

 Sextus, therefore, though a skeptic by profession, was not insensible to 

 the difference between experimental knowledge and mystical dogmas, 

 though even the former had nothing wdiich excited his admiration. 



The skepticism which denies the evidence of the truths of which 

 the best established physical sciences consist, must necessarily involve 

 a very indistinct apprehension of those truths ; for such truths, prop- 

 erly exhibited, contain their own evidence, and are the best antidote 

 Vol. I.— 13 



