LOGIC OF PRACTICE OR ART. 615 



or the physician who preferred that his patients should 

 die by rule rather than recover contrary to it, is 

 rightly judged to be a mere pedant, and the slave of 

 his formulas. 



Now, the reasons of a maxim of policy, or of any 

 other rule of art, can be no other than the theorems 

 of the corresponding science. 



The relation in which rules of art stand to doc- 

 trines of science may be thus characterized. The art 

 proposes to itself an end to be attained, defines the 

 end, and hands it over to the science. The science 

 receives it, considers it as a phenomenon or effect to 

 be studied, and having investigated its causes and 

 conditions^, sends it back to Art with a theorem of the 

 combinations of circumstances by which it could be 

 produced. Art then examines these combinations of 

 circumstances, and according as any of them are or 

 are not in human power, pronounces the end attain- 

 able or not. The only one of the premisses, there- 

 fore, which Art supplies, is the original major premiss, 

 which asserts that the attainment of the given end is 

 desirable. Science then lends to Art the proposition 

 (obtained by a series of inductions or of deductions) 

 that the performance of certain actions will attain the 

 end. From these premisses Art concludes that the 

 performance of these actions is desirable, and finding 

 it also practicable, converts the theorem into a rule or 

 precept. 



3. It deserves particular notice, that the theorem 

 or speculative truth is not ripe for being turned into 

 a precept, until all that part of the operation which 

 belongs to science has been completely performed. 

 Suppose that we have completed the scientific process 

 only up to a certain point; have discovered that a 



