TRANSFORMATION AND EQUIVALENCE OF FORCES. 211 



others more or less transformed. And besides recognizing 

 this necessary linking of the forces at any time manifested, 

 with those preceding and succeeding them, we must recog- 

 nize the amounts of these forces as determinate — as neces- 

 sarily producing such and such quantities of results, and as 

 necessarily limited to those quantities. 



That unification of knowledge which is the business of 

 Philosophy, is but little furthered by the establishment of 

 this truth under its general form. We must trace it out 

 under its leading special forms. Changes, and the accom- 

 panying transformations of forces, are everywhere in pro- 

 gress, from the movements of stars to the currents of our 

 thoughts; and to comprehend, in any adequate way, the 

 meaning of the great fact that forces, unceasingly metamor- 

 phosed, are nowhere increased or decreased, it is requisite 

 for us to contemplate the various orders of changes going on 

 around, for the purpose of ascertaining whence arise the 

 forces they imply and what becomes of these forces. Of 

 course if answerable at all, these questions can be answered 

 only in the rudest way. We cannot hope to establish 

 equivalence among the successive manifestations of force. 

 The most we can hope is to establish a qualitative correla- 

 tion that is indefinitely quantitative — quantitative to the 

 extent of involving something like a due proportion between 

 causes and effects. 



Let us, with the view of trying to do this, consider in 

 succession the several classes of phenomena which the sev- 

 eral concrete sciences deal with. 



§ 68. The antecedents of those forces which our Solar 

 System displays, belong to a past of which we can never 

 have anything but inferential knowledge ; and at present we 

 cannot be said to have even this. Numerous and strong as 

 are the reasons for believing the Nebular Hypothesis, we 

 cannot yet regard it as more than an hypothesis. If, how- 

 ever, we assume that the matter composing the Solar System 



