30 COSMOS. 



purely rational science of nature, and is simply a physical 

 geography, combined with a description of the regions oj space 

 and the bodies occupying them. Devoid of the profoundness of 

 a purely speculative philosophy, my essay 011 the Cosmos treats 

 of the contemplation of the universe, and is based upon a 

 rational empiricism, that is to say, upon the results of the 

 facts registered by science, and tested by the operations of the 

 intellect. It is within these limits alone that the work, which 

 I now venture to undertake, appertains to the sphere of 

 labour, to which I have devoted myself throughout the 

 course of my long scientific career. This path of enquiry is 

 not unknown to me, although it may be pursued by others 

 with greater success. The unity which I seek to attain in the 

 development of the great phenomena of the universe, is 

 analogous to that which historical composition is capable 

 of acquiring. All points relating to the accidental indi- 

 vidualities, and the essential variations of the actual, whether 

 in the form and arrangement of natural objects in the struggle 

 of man against the elements, or of nations against nations, 

 do not admit of being based only on a rational foundation 

 that is to say, of being deduced from ideas alone. 



It seems to me that a like degree of empiricism attaches to 

 the Description of the Universe and to Civil History ; but in 

 reflecting upon physical phenomena and events, and tracing 

 their causes by the process of reason, we become more and 

 more convinced of the truth of the ancient doctrine, that the 

 forces inherent in matter, and those which govern the moral 

 world, exercise their action under the control of primordial 

 necessity, and in accordance with movements occurring periodi- 

 cally after longer or shorter intervals. 



It is this necessity, this occult but permanent connection, 

 this periodical recurrence in the progressive development of 

 forms, phenomena, and events, which constitute nature, obedi- 

 ent to the first impulse imparted to it. Physics, as the term 

 signifies, is limited to the explanation of the phenomena of 

 the material world by the properties of matter. The ultimate 

 object of the experimental sciences is, therefore, to discover 

 laws, and to trace their progressive generalization. All tjiat 

 exceeds this goes beyond the province of the physical descrip- 

 tion of the universe, and appertains to a range of higher 

 speculative views. 



