what might perhaps bring some profit to the living, 

 when we have in view the accomplishment of other 

 ends that will be of much greater advantage to 

 posterity. And in truth, I am quite willing it 

 should be known that the little I have hitherto 

 learned is almost nothing in comparison with that of 

 which I am ignorant, and to the knowledge of which 

 I do not despair of being able to attain for it is 

 much the same with those who gradually discover 

 truth in the Sciences, as with those who when 

 growing rich find less difficulty in making great 

 acquisitions, than they formerly experienced when 

 poor in making acquisitions of much smaller 

 amount. Or they may be compared to the com- 

 manders of arr/iies, whose forces usually increase in 

 proportion to their victories, and who need greater 

 prudence to keep together the residue of their troops 

 after a defeat than after a victory to take towns and 

 provinces. For he truly engages in battle who 

 endeavours to surmount all the difficulties and errors 

 which prevent him from reaching the knowledge of 

 truth, and he is overcome in fight who admits a false 

 opinion touching a matter of any generality and 

 importance, and he requires thereafter much more 

 skill to recover his former position than to make 

 great advances when once in possession of thor- 

 oughly ascertained principles. As for myself, if I 

 have succeeded in discovering any truths in the 

 Sciences, (and I trust that what is contained in this 

 volume* will show that I have found some,) I can 

 declare that they are but the consequences and 



*See p. 31, footnote. 



