OF THE SPIRIT. 281 



This process was first introduced in the mathematical 

 and dynamical sciences, and in the more or less suc- 

 cessful attempts to reduce other branches of natural 

 science such as acoustics, optics, thermotics, electrics, 

 chemistry, and biology, to a study of mechanical pro- 

 cesses, which possess merely quantitative (easily measu- 

 rable) in the place of qualitative differences. It went 

 hand in hand, in the region of psychology, with the 

 distinction of primary and secondary qualities : the 

 former, such as size, figure, and resistance being 

 measurable, more permanent and objective, as com- 

 pared with the latter, such as colour, sound, and heat, 

 which are subjective and difficult to fix. Being ob- 

 jective, i.e., the same or similar to different observers, 

 the former acquire the character of greater reality, 

 whereas they only possess, in the world of our ex- 

 perience, more definiteness, more stability, and more 

 permanence ; they can also be easily reproduced in 

 diagrams and models and recalled by the powers of 

 memory. All these advantages make them more think- 

 able or intelligible, for they do not disappear so easily out 

 of our mental field of vision as the sensations of colour, 

 heat, taste, smell, or the numerous and ever-changing 

 inner sensations, such as those of effort and emotion. 



Thus it came about that the so-called primary quali- 



thought." With most persons this 

 breaking up of the original synoptic 

 aspect, the primary self, is carried 

 as far as intersubjective communi- 

 cation with other persons through 

 the aid of language, and the in- 

 terests of life and practical work 

 make it necessary. Science only these notions, 

 carries this process a step further 



through what is termed ' ' analysis 

 and synthesis " of ideas, using ideas 

 in the sense of Hume. This 

 process of analysis or synthesis 

 reaches perfection only in the 

 notions of number and space, and 

 in the sciences that work with 



