552 LOGIC OF THE MORAL SCIENCES. 



an adviser for practice. His part is only to show that certain 

 consequences follow from certain causes, and that to obtain 

 certain ends, certain means are the most effectual. Whether 

 the ends themselves are such as ought to he pursued, and if 

 so, in what cases and to how great a length, it is no part of 

 his business as a cultivator of science to decide, and science 

 alone will never qualify him for the decision. In purely 

 physical science, there is not much temptation to assume this 

 ulterior office ; but those who treat of human nature and 

 society invariably claim it; they always undertake to say, 

 not merely what is, but what ought to be. To entitle them 

 to do this, a complete doctrine of Teleology is indispensable. 

 A scientific theory, however perfect, of the subject matter, 

 considered merely as part of the order of nature, can in no 

 degree serve as a substitute. In this respect the various 

 subordinate arts afford a misleading analogy. In them there 

 is seldom any visible necessity for justifying the end, since in 

 general its desirableness is denied by nobody, and it is only 

 when the question of precedence is to be decided between that 

 end and some other, that the general principles of Teleology 

 have to be called in : but a writer on Morals and Politics 

 requires those principles at every step. The most elaborate 

 and well-digested exposition of the laws of succession and 

 coexistence among mental or social phenomena, and of their 

 relation to one another as causes and effects, will be of no 

 avail towards the art of Life or of Society, if the ends to be 

 aimed at by that art are left to the vague suggestions of the 

 intellectus sibi permissus, or are taken for granted without 

 analysis or questioning. 



7. There is, then, a Philosophia Prima peculiar to 

 Art, as there is one which belongs to Science. There are not 

 only first principles of Knowledge, but first principles of 

 Conduct There must be some standard by which to deter- 

 mine the goodness or badness, absolute and comparative, of 

 ends, or objects of desire. And whatever that standard is, 

 there can be but one : for if there were several ultimate prin- 

 ciples of conduct, the same conduct might be approved by 



