SPENCER AND THE SYNTHETIC PHILOSOPHY. 9 



Then the answer given is firmly established npon the doctrine 

 of a gradual unfolding of the mental faculties in obedience to 

 natural law, the unfolding taking the form of a double-sided 

 change from the simple to the complex, and from the indefinite 

 to the definite. So is it with all other subjects whatsoever. In 

 the essay on Manners and Fashions, for example, emphasis is laid 

 upon the truths that the various forms of restraint exercised by 

 society as an aggregate over its individual members such re- 

 straints being now clearly differentiated into ecclesiastical, politi- 

 cal, and ceremonial are all natural developments from one pri- 

 mordial form, and that the divergence of one from the other and 

 of all from such primordial form takes place "in conformity 

 with the laws of evolution of all organized bodies." And once 

 again a similar line of argument is followed out in the extremely 

 attractive articles on the Genesis of Science and The Origin and 

 Function of Music. Finally, in the elaborate essay on Progress : 

 its Law and Cause, evolutionary principles are enunciated with 

 the utmost distinctness. The law of progress is shown to con- 

 sist in the transformation of the homogeneous into the hetero- 

 geneous (a partial statement afterward completed by the addition 

 of a factor for the time being overlooked *) ; and this process is 

 illustrated by examples taken from all orders of phenomena, 

 while the cause of the transformation is found in the law of the 

 multiplication of effects, afterward brought out more fully in 

 First Principles. In this essay, too, as in that on the Develop- 

 ment Hypothesis, the general law of evolution is presented as 

 holding good in the production of species and varieties, though 

 here again direct adaptation to the conditions of existence is the 

 only factor recognized as playing a part in the stupendous drama 

 of unfolding life. 



I have said enough, I think, to show how active was the period 

 with which we have just been dealing active alike in original 

 production and in the absorption of fresh material and the or- 

 ganization of new ideas. But the enumeration of these five-and- 

 twenty essays does not exhaust the record of Spencer's labors dur- 

 ing this time. His studies in psychology, of which the essays on 

 The Universal Postulate (1853) and The Art of Education (1854) 

 were the immediate results, took more systematic form about the 

 date of the publication of the latter paper ; and in 1855 the first 

 edition of his Principles of Psychology made its appearance. As 

 this work was subsequently included as a portion of the two vol- 

 umes on the Principles of Psychology in the synthetic system, 

 any analysis of its contents does not fall within the scope of the 

 present paper. Two remarks may, however, be appropriately made 



* This additional factor being increase in definiteness. A change must consist in in- 

 creasing heterogeneity and increasing definiteness, to constitute evolution. 



