DISCOURSE ON METHOD. 47 



accordance with these laws, dispose and arrange 

 itself in such a way as to present the appearance of 

 heavens; how in the meantime some of its parts 

 must compose an earth and some planets and comets, 

 and others a sun and fixed stars. And, making a 

 digression at this stage on the subject of light, I 

 expounded at considerable length what the nature 

 of that light must be which is found in the sun and 

 the stars, and how thence in an instant of time it 

 traverses the immense spaces of the heavens, and 

 how from the planets and comets it is reflected 

 towards the earth. To this I likewise added much 

 respecting the substance, the situation, the motions, 

 and all the different qualities of these heavens and 

 stars ; so that I thought I had said enough respect- 

 ing them to show that there is nothing observable in 

 the heavens or stars of our system that must not, or 

 at least may not, appear precisely alike in those of 

 the system whicli I described. I came next to 

 speak of the earth in particular, and to show how, 

 even though I had expressly supposed that God had 

 given no weight to the matter of which it is com- 

 posed, this should not prevent all its parts from 

 tending exactly to its centre ; how with water and 

 air on its surface, the disposition of the heavens and 

 heavenly bodies, more especially of the moon, must 

 cause a flow and ebb, like in all its circumstances to 

 that observed in our seas, as also a certain current 

 both of water and air from east to west, such as is 

 likewise observed between the tropics; how the 

 mountains, seas, fountains, and rivers might natur- 

 ally be formed in it, and the metals produced in the 



