468 COSMOS. 



often guides almost imperceptibly the course of presage, ele- 

 vating it as by a power of inspiration. How much has been 

 enounced amongst the Indians and Greeks, and during the 

 middle ages, regarding the connection of natural phenomena, 

 which, at first, either vague, or blended with the most un- 

 founded hypotheses, has, at a subsequent epoch, been confirmed 

 by sure experience, and then been recognised as a scientific 

 truth ! The presentient fancy and the vivid activity of spirit 

 which animated Plato, Columbus, and Kepler, must not be 

 disregarded, as if they had effected nothing in the domain of 

 science, or as if they tended, of necessity, to draw the mind 

 from" the investigation of the actual. 



As we have defined the history of the physical contempla- 

 tion of the universe to be the history of the recognition of nature 

 in the unity of its phenomena, and of the connection of the 

 forces of the universe, our mode of proceeding must consist in 

 the enumeration of those subjects by which the idea of the 

 unity of the phenomena has been gradually developed. We 

 would here distinguish : 



1 . The independent efforts of reason to acquire a knowledge 

 of natural laws, by a meditative consideration of the pheno- 

 mena of nature. 



2. Events in the history of the world which have suddenly 

 enlarged the horizon of observation. 



3. The discovery of new means of sensuous perception, 

 as well as the discovery of new organs by which men have 

 been brought into closer connection, both with terrestrial 

 objects and with remote regions of space. 



This threefold view serves as a guide in defining the prin- 

 cipal epochs that characterise the history of the science of the 

 Cosmos. For the purpose of further illustration I would 

 ttgain adduce some examples indicative of the diversity of the 

 means by which mankind attained to the intellectual posses- 

 sion of a great portion of the universe. Under this head I 

 include examples of an enlarged field of natural knowledge, 

 great historical events, and the discovery of new organs. 



The knowledge of nature, as it existed amongst the Hellenic 

 nations under the most ancient forms of physics, was derived 

 more from the depth of mental contemplation than from the 

 sensuous consideration of phenomena. Thus the natural phi- 

 losophy of the Ionian physiologists was directed to the funda- 



