280 PREFACE TO THE 



his philosophical life, Leibnitz was disposed to agree 

 with the opinion common among the reformers of 

 philosophy, that what Aristotle had said of matter, of 

 form, and of mutation, was to be explained by means 

 of magnitude, figure, and motion. This opinion he 

 ascribes to all the reformers of the seventeenth cen 

 tury, mentioning by name Bacon and several others. 1 

 Thirty years afterwards, in giving some account of 

 the history of his opinions, he says that he came to 

 perceive, &quot; que la seule consideration d une masse eten- 

 due ne suffisoit pas, et qu il falloit employer encore la 

 notion de la force, qui est tres-intelligible, quoiqu elle 

 solt du ressort de la Me taphysique.&quot; 2 In introduc 

 ing this notion of force, he conceived that he was re 

 habilitating the Aristotelian or scholastic philosophy, 

 seeing &quot; que les formes des Anciens ou Entelechies 

 ne sont autre chose que les forces.&quot; 3 These primi 

 tive forces 4 being the constituent forms of substances, 

 he supposed them, with one exception (founded on doo-- 

 matic grounds), to have been created at the beginning 

 of the world. The &quot;lex a Deo lata&quot; at the creation 

 &quot; reliquit aliquod sui expressum in rebus vestigium,&quot; 

 namely an efficacy, or form, or force, by virtue of 

 which and in accordance with the divine precept all 

 phenomena had been engendered. 5 



If we compare these expressions, which contain the 

 fundamental idea of Leibnitz s philosophy, with those 

 which have already been quoted from the following 

 tract, we shall I think perceive more than an acci- 



1 Epist. ad Thomas, p. 48. of Erdmann s edition of Leibnitz s Phil. Works. 



2 Systeme nouveau, p. 124., Erdmann. 

 8 Lettre ii Bouvet, p. 140,, Enlmann. 



* Forces primitives, v. Syst. Nouv. 

 6 See his De ipsa Xatiirii, p. 156. 



