PROGRESS OF THE ARTS. 351 



Induction ; and the attempt must be reserved for 

 another place : but the leading differences are suf- 

 ficiently obvious. Art is practical, Science is spe- 

 culative : the former is seen in doing ; the latter 

 rests in the contemplation of what is known. The 

 Art of the builder appears in his edifice, though 

 he may never have meditated on the abstract pro- 

 positions on which its stability and strength de- 

 pends. The Science of the mathematical mechani- 

 cian consists in his seeing that, under certain con- 

 ditions, bodies must sustain each other's pressure, 

 though he may never have applied his knowledge 

 in a single case. 



Now the remark which I have to make is this : 

 in all cases the Arts are prior to the related 

 Sciences. Art is the parent, not the progeny, of 

 Science ; the realization of principles in practice 

 forms part of the prelude, as well as of the sequel, 

 of theoretical discovery. And thus the inventions 

 of the middle ages, which have been above enu- 

 merated, though at the present day they may be 

 portions of our sciences, are no evidence that the 

 sciences then existed ; but only that those powers 

 of practical observation and practical skill were 

 at work, which prepare the way for theoretical 

 views and scientific discoveries. 



It may be urged, that the great works of art 

 do virtually take for granted principles of science ; 

 and that, therefore, it is unreasonable to deny 

 science to great artists. It may be said, that the 



