THE SCOPE OF BIOLOGY. 127 



rangement of organisms, that if certain structural attributes 

 of any one be given, its other structural attributes may be 

 empirically predicted; and which prepares the way for that 

 interpretation of their relations and genesis, which forms an 

 important part of rational Biology. 



§ 39. The second main division of Biology, above described 

 as embracing the functional phenomena of organisms, is that 

 which is in part signified by Physiology: the remainder 

 being distinguishable as Objective Psychology. Both of these 

 fall into subdivisions that may best be treated separately. 



That part of Physiology which is concerned with the 

 molecular changes going on in organisms, is known as 

 Organic Chemistry. An account of the modes in which the 

 force generated in organisms by chemical change, is trans- 

 formed into other forces, and made to work the various 

 organs that carry on the functions of Life, comes under the 

 head of Organic Physics. Psychology, which is 



mainly concerned with the adjustment of vital actions to 

 actions in the environment (in contrast with Physiology, 

 which is mainly concerned with vital actions apart from 

 actions in the environment) consists of two quite distinct 

 portions. Objective Psychology deals with those functions 

 of the nervo-muscular apparatus by which such organisms 

 as possess it are enabled to adjust inner to outer relations; 

 and includes also the study of the same functions as exter- 

 nally manifested in conduct. Subjective Psychology deals 

 with the sensations, perceptions, ideas, emotions, and volitions 

 that are the direct or indirect concomitants of this visible 

 adjustment of inner to outer relations. Consciousness under 

 its different modes and forms, being a subject-matter radically 

 distinct in nature from the subject-matter of Biology in 

 general ; and the method of self-analysis, by which alone the 

 laws of dependence among changes of consciousness can be 

 found, being a method unparalleled by anything in the rest 

 of Biology; we are obliged to regard Subjective Psychology 



