Mental Discipline in Implication. 435 



conscious of in ourselves, and observe in one another. Such. fr 

 ex.imple, arc the laws of association. Psychology, so far as it 

 consists of such laws (I speak of the laws themselves, not of their 

 disputed applications), is as positive and certain a science as chemis- 

 try, and fit to be taught as such. 



The discipline and the knowledge conferred by study of 

 'the preceding group of sciences form the true preparation 

 for that higher class of studies, mental, moral, political, and 

 literary, which completes the course of a true liberal educa- 

 tion. Although not themselves ranked as sciences, these 

 extensive and important subjects are constantly becoming 

 more and more scientific in their conceptions and methods, 

 and hence form the natural sequel of a systematic scientific 

 culture. Physiology passes insensibly into psychology, the 

 central science, upon which hinge logic, sociology, political 

 economy, history, ethics, aesthetics, and literature. Mental 

 phenomena are manifestations of life, and their laws are 

 derivatives of the laws of life ; only throngh a knowledge 

 of the former, therefore, is it possible to reach a true un- 

 derstanding of the latter. Logic treats of the laws of evi- 

 dence and proof, by which things and their relations are 

 truly represented in thought.* Sociology considers the re- 

 lations among human beings and the forces which act upon 

 them in society, and it hence only becomes possible through 

 a prior knowledge of the vital and mental organization of 

 man ; political economy, a branch of this subject, treating 

 of industrial and commercial questions, depends upon the 

 same conditions. History is a record of the course of 

 human experience in its multiform phases, and the key to 

 its right interpretation is that knowledge of the character 

 of the Actor and the circumstances of action which it is the 

 prerogative of science alone to give. Ethics, or moral 

 science, determines the principles which should guide the 

 right ruling of conduct, and depends upon every science 



* See page 45. 



